|  | @@ 215-228 (lines=14) @@ | 
                                                            
                                    | 212 |  |      * | 
                                                            
                                    | 213 |  |      * @return object|null The related resource if found else null | 
                                                            
                                    | 214 |  |      */ | 
                                                            
                                    | 215 |  |     public function getRelatedResourceReference( | 
                                                            
                                    | 216 |  |         ResourceSet $sourceResourceSet, | 
                                                            
                                    | 217 |  |         $sourceEntityInstance, | 
                                                            
                                    | 218 |  |         ResourceSet $targetResourceSet, | 
                                                            
                                    | 219 |  |         ResourceProperty $targetProperty | 
                                                            
                                    | 220 |  |     ) { | 
                                                            
                                    | 221 |  |         if (!($sourceEntityInstance instanceof Model)) { | 
                                                            
                                    | 222 |  |             throw new InvalidArgumentException('Source entity must be an Eloquent model.'); | 
                                                            
                                    | 223 |  |         } | 
                                                            
                                    | 224 |  |         $this->checkSourceInstance($sourceEntityInstance); | 
                                                            
                                    | 225 |  |  | 
                                                            
                                    | 226 |  |         $propertyName = $targetProperty->getName(); | 
                                                            
                                    | 227 |  |         return $sourceEntityInstance->$propertyName; | 
                                                            
                                    | 228 |  |     } | 
                                                            
                                    | 229 |  |  | 
                                                            
                                    | 230 |  |     /** | 
                                                            
                                    | 231 |  |      * Gets a related entity instance from an entity set identified by a key | 
                                                                                
                                |  | @@ 242-254 (lines=13) @@ | 
                                                            
                                    | 239 |  |      * | 
                                                            
                                    | 240 |  |      * @return object|null Returns entity instance if found else null | 
                                                            
                                    | 241 |  |      */ | 
                                                            
                                    | 242 |  |     public function getResourceFromRelatedResourceSet( | 
                                                            
                                    | 243 |  |         ResourceSet $sourceResourceSet, | 
                                                            
                                    | 244 |  |         $sourceEntityInstance, | 
                                                            
                                    | 245 |  |         ResourceSet $targetResourceSet, | 
                                                            
                                    | 246 |  |         ResourceProperty $targetProperty, | 
                                                            
                                    | 247 |  |         KeyDescriptor $keyDescriptor | 
                                                            
                                    | 248 |  |     ) { | 
                                                            
                                    | 249 |  |         if (!($sourceEntityInstance instanceof Model)) { | 
                                                            
                                    | 250 |  |             throw new InvalidArgumentException('Source entity must be an Eloquent model.'); | 
                                                            
                                    | 251 |  |         } | 
                                                            
                                    | 252 |  |         $propertyName = $targetProperty->getName(); | 
                                                            
                                    | 253 |  |         return $this->getResource(null, $keyDescriptor, [], $sourceEntityInstance->$propertyName); | 
                                                            
                                    | 254 |  |     } | 
                                                            
                                    | 255 |  |  | 
                                                            
                                    | 256 |  |  | 
                                                            
                                    | 257 |  |     /** |