| 1 |  |  | <?php | 
            
                                                                                                            
                            
            
                                    
            
            
                | 2 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 3 |  |  | namespace Metabor\Statemachine\Util; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 4 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 5 |  |  | use Metabor\Statemachine\State; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 6 |  |  | use Metabor\Statemachine\StateCollection; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 7 |  |  | use Metabor\Statemachine\Transition; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 8 |  |  | use MetaborStd\MergeableInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 9 |  |  | use MetaborStd\MetadataInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 10 |  |  | use MetaborStd\WeightedInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 11 |  |  | use MetaborStd\Statemachine\StateCollectionInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 12 |  |  | use MetaborStd\Statemachine\StateInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 13 |  |  | use MetaborStd\Statemachine\TransitionInterface; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 14 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 15 |  |  | /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 16 |  |  |  * @author Oliver Tischlinger | 
            
                                                                                                            
                            
            
                                    
            
            
                | 17 |  |  |  */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 18 |  |  | class StateCollectionMerger implements MergeableInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 19 |  |  | { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 20 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 21 |  |  |      * @var StateCollectionInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 22 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 23 |  |  |     private $targetCollection; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 24 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 25 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 26 |  |  |      * @var string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 27 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 28 |  |  |     private $stateNamePrefix; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 29 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 30 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 31 |  |  |      * @param StateCollectionInterface $targetCollection | 
            
                                                                                                            
                            
            
                                    
            
            
                | 32 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 33 |  |  |     public function __construct(StateCollectionInterface $targetCollection) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 34 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 35 | 4 |  |         $this->targetCollection = $targetCollection; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 36 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 37 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 38 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 39 |  |  |      * @return string | 
            
                                                                                                            
                            
            
                                    
            
            
                | 40 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 41 |  |  |     public function getStateNamePrefix() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 42 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 43 |  |  |         return $this->stateNamePrefix; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 44 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 45 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 46 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 47 |  |  |      * @param string $stateNamePrefix | 
            
                                                                                                            
                            
            
                                    
            
            
                | 48 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 49 |  |  |     public function setStateNamePrefix($stateNamePrefix) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 50 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 51 |  |  |         $this->stateNamePrefix = $stateNamePrefix; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 52 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 53 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 54 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 55 |  |  |      * @return \MetaborStd\Statemachine\StateCollectionInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 56 |  |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 57 |  |  |     public function getTargetCollection() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 58 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 59 |  |  |         return $this->targetCollection; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 60 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 61 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 62 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 63 |  |  |      * @param string $name | 
            
                                                                                                            
                            
            
                                    
            
            
                | 64 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 65 |  |  |      * @return \MetaborStd\Statemachine\StateInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 66 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 67 |  |  |     protected function createState($name) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 68 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 69 |  |  |         return new State($name); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 70 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 71 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 72 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 73 |  |  |      * @param StateInterface      $sourceState | 
            
                                                                                                            
                            
            
                                    
            
            
                | 74 |  |  |      * @param TransitionInterface $sourceTransition | 
            
                                                                                                            
                            
            
                                    
            
            
                | 75 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 76 |  |  |      * @throws \InvalidArgumentException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 77 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 78 |  |  |     protected function addTransition(StateInterface $sourceState, TransitionInterface $sourceTransition) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 79 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 80 | 4 |  |         if ($sourceState instanceof State) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 81 | 4 |  |             $sourceState->addTransition($sourceTransition); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 82 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 83 |  |  |             throw new \InvalidArgumentException('Overwrite this method to implement a different type!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 84 | 4 |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 85 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 86 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 87 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 88 |  |  |      * @param TransitionInterface $sourceTransition | 
            
                                                                                                            
                            
            
                                    
            
            
                | 89 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 90 |  |  |      * @throws \InvalidArgumentException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 91 |  |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 92 |  |  |      * @return \Metabor\Statemachine\Transition | 
            
                                                                                                            
                            
            
                                    
            
            
                | 93 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 94 |  |  |     protected function createTransition(TransitionInterface $sourceTransition) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 95 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 96 | 4 |  |         $targetStateName = $sourceTransition->getTargetState()->getName(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 97 | 4 |  |         $targetState = $this->findOrCreateState($targetStateName); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 98 | 4 |  |         $this->mergeMetadata($sourceTransition->getTargetState(), $targetState); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 99 |  |  |         $eventName = $sourceTransition->getEventName(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 100 | 4 |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 101 | 3 |  |         if ($sourceTransition->getConditionName()) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 102 | 3 |  |             if ($sourceTransition instanceof Transition) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 103 | 3 |  |                 $condition = $sourceTransition->getCondition(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 104 |  |  |             } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 105 |  |  |                 throw new \InvalidArgumentException('Overwrite this method to implement a different type!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 106 | 3 |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 107 | 4 |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 108 |  |  |             $condition = null; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 109 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 110 | 4 |  |          | 
            
                                                                                                            
                            
            
                                    
            
            
                | 111 |  |  |         if ($sourceTransition instanceof WeightedInterface) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 112 |  |  |             $transition->setWeight($sourceTransition->getWeight()); | 
                            
                    |  |  |  | 
                                                                                        
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                | 113 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 114 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 115 |  |  |         return new Transition($targetState, $eventName, $condition); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 116 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 117 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 118 |  |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 119 | 4 |  |      * @param object $source | 
            
                                                                                                            
                            
            
                                    
            
            
                | 120 |  |  |      * @param object $target | 
            
                                                                                                            
                            
            
                                    
            
            
                | 121 | 4 |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 122 | 4 |  |      * @throws \RuntimeException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 123 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 124 | 4 |  |     protected function mergeMetadata($source, $target) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 125 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 126 | 3 |  |         if ($source instanceof \ArrayAccess) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 127 | 4 |  |             if ($target instanceof \ArrayAccess) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 128 | 4 |  |                 if ($source instanceof MetadataInterface) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 129 |  |  |                     $metadata = $source->getMetadata(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 130 |  |  |                     foreach ($metadata as $offset => $value) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 131 | 4 |  |                         $target->offsetSet($offset, $value); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 132 |  |  |                     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 133 | 1 |  |                 } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 134 | 4 |  |                     throw new \RuntimeException('Source had to make all metadata available!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 135 | 4 |  |                 } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 136 |  |  |             } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 137 |  |  |                 throw new \RuntimeException('Source metadata can not be merged!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 138 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 139 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 140 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 141 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 142 | 4 |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 143 |  |  |      * @param StateInterface $state | 
            
                                                                                                            
                            
            
                                    
            
            
                | 144 | 4 |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 145 | 4 |  |      * @throws \InvalidArgumentException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 146 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 147 |  |  |     protected function addState(StateInterface $state) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 148 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 149 | 4 |  |         if ($this->targetCollection instanceof StateCollection) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 150 |  |  |             $this->targetCollection->addState($state); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 151 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 152 |  |  |             throw new \InvalidArgumentException('TargetCollection has to be a StateCollection. Overwrite this method to implement a different type!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 153 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 154 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 155 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 156 | 4 |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 157 |  |  |      * @param string $name | 
            
                                                                                                            
                            
            
                                    
            
            
                | 158 | 4 |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 159 | 4 |  |      * @return \MetaborStd\Statemachine\StateInterface | 
            
                                                                                                            
                            
            
                                    
            
            
                | 160 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 161 | 4 |  |     protected function findOrCreateState($name) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 162 | 4 |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 163 | 4 |  |         $name = $this->stateNamePrefix . $name; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 164 |  |  |         if ($this->targetCollection->hasState($name)) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 165 |  |  |             $targetState = $this->targetCollection->getState($name); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 166 | 4 |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 167 |  |  |             $targetState = $this->createState($name); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 168 |  |  |             $this->addState($targetState); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 169 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 170 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 171 |  |  |         return $targetState; | 
            
                                                                                                            
                            
            
                                    
            
            
                | 172 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 173 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 174 | 4 |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 175 |  |  |      * @param StateInterface $sourceState | 
            
                                                                                                            
                            
            
                                    
            
            
                | 176 | 4 |  |      * | 
            
                                                                                                            
                            
            
                                    
            
            
                | 177 | 4 |  |      * @throws \InvalidArgumentException | 
            
                                                                                                            
                            
            
                                    
            
            
                | 178 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 179 |  |  |     protected function mergeState(StateInterface $sourceState) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 180 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 181 | 4 |  |         $name = $sourceState->getName(); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 182 | 4 |  |         $targetState = $this->findOrCreateState($name); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 183 | 4 |  |         $this->mergeMetadata($sourceState, $targetState); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 184 | 4 |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 185 |  |  |         /* @var $transition TransitionInterface */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 186 | 4 |  |         foreach ($sourceState->getTransitions() as $sourceTransition) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 187 | 4 |  |             $targetTransition = $this->createTransition($sourceTransition); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 188 | 4 |  |             $this->addTransition($targetState, $targetTransition); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 189 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 190 | 4 |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 191 |  |  |         foreach ($sourceState->getEventNames() as $eventName) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 192 | 4 |  |             $sourceEvent = $sourceState->getEvent($eventName); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 193 | 3 |  |             $targetEvent = $targetState->getEvent($eventName); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 194 | 4 |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 195 | 4 |  |             $this->mergeMetadata($sourceEvent, $targetEvent); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 196 | 4 |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 197 |  |  |             foreach ($sourceEvent->getObservers() as $observer) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 198 |  |  |                 $targetEvent->attach($observer); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 199 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 200 | 4 |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 201 |  |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 202 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 203 | 4 |  |     /** | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 204 | 4 |  |      */ | 
            
                                                                        
                            
            
                                    
            
            
                | 205 | 4 |  |     protected function mergeStateCollection(StateCollectionInterface $source) | 
            
                                                                        
                            
            
                                    
            
            
                | 206 | 4 |  |     { | 
            
                                                                        
                            
            
                                    
            
            
                | 207 |  |  |         /* @var $sourceState StateInterface */ | 
            
                                                                        
                            
            
                                    
            
            
                | 208 |  |  |         foreach ($source->getStates() as $sourceState) { | 
            
                                                                        
                            
            
                                    
            
            
                | 209 |  |  |             $this->mergeState($sourceState); | 
            
                                                                        
                            
            
                                    
            
            
                | 210 |  |  |         } | 
            
                                                                        
                            
            
                                    
            
            
                | 211 | 4 |  |     } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 212 |  |  |  | 
            
                                                                                                            
                            
            
                                    
            
            
                | 213 | 4 |  |     /** | 
            
                                                                                                            
                            
            
                                    
            
            
                | 214 | 4 |  |      * @see \MetaborStd\MergeableInterface::merge() | 
            
                                                                                                            
                            
            
                                    
            
            
                | 215 | 4 |  |      */ | 
            
                                                                                                            
                            
            
                                    
            
            
                | 216 |  |  |     public function merge($source) | 
            
                                                                                                            
                            
            
                                    
            
            
                | 217 |  |  |     { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 218 |  |  |         if ($source instanceof StateCollectionInterface) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 219 |  |  |             $this->mergeStateCollection($source); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 220 |  |  |         } elseif ($source instanceof StateInterface) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 221 |  |  |             $this->mergeState($source); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 222 |  |  |         } elseif ($source instanceof \Traversable) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 223 |  |  |             foreach ($source as $value) { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 224 | 4 |  |                 $this->merge($value); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 225 |  |  |             } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 226 |  |  |         } else { | 
            
                                                                                                            
                            
            
                                    
            
            
                | 227 |  |  |             throw new \InvalidArgumentException('Source can not be merged!'); | 
            
                                                                                                            
                            
            
                                    
            
            
                | 228 |  |  |         } | 
            
                                                                                                            
                            
            
                                    
            
            
                | 229 |  |  |     } | 
            
                                                                                                            
                                                                
            
                                    
            
            
                | 230 |  |  | } | 
            
                                                        
            
                                    
            
            
                | 231 |  |  |  | 
            
                        
This check looks for variables that are accessed but have not been defined. It raises an issue if it finds another variable that has a similar name.
The variable may have been renamed without also renaming all references.