Duplicate code is one of the most pungent code smells. A rule that is often used is to re-structure code once it is duplicated in three or more places.
Common duplication problems, and corresponding solutions are:
| 1 | <?php  | 
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| 16 | class Credential extends DataObject  | 
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| 17 | { | 
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| 18 | /** @var int */  | 
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| 19 | private $user;  | 
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| 20 | /** @var int */  | 
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| 21 | private $factor;  | 
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| 22 | /** @var string */  | 
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| 23 | private $type;  | 
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| 24 | /** @var string */  | 
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| 25 | private $data;  | 
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| 26 | /** @var int */  | 
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| 27 | private $version;  | 
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| 28 | private $timeout;  | 
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| 29 | /** @var int */  | 
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| 30 | private $disabled = 0;  | 
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| 31 | /** @var int */  | 
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| 32 | private $priority;  | 
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| 33 | |||
| 34 | /**  | 
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| 35 | * @return int  | 
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| 36 | */  | 
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| 37 | public function getUserId()  | 
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| 41 | |||
| 42 | /**  | 
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| 43 | * @param int $user  | 
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| 44 | */  | 
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| 45 | public function setUserId($user)  | 
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| 49 | |||
| 50 | /**  | 
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| 51 | * @return int  | 
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| 52 | */  | 
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| 53 | public function getFactor()  | 
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| 57 | |||
| 58 | /**  | 
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| 59 | * @param int $factor  | 
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| 60 | */  | 
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| 61 | public function setFactor($factor)  | 
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| 65 | |||
| 66 | /**  | 
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| 67 | * @return string  | 
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| 68 | */  | 
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| 69 | public function getType()  | 
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| 73 | |||
| 74 | /**  | 
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| 75 | * @param string $type  | 
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| 76 | */  | 
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| 77 | public function setType($type)  | 
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| 81 | |||
| 82 | /**  | 
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| 83 | * @return string  | 
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| 84 | */  | 
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| 85 | public function getData()  | 
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| 89 | |||
| 90 | /**  | 
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| 91 | * @param string $data  | 
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| 92 | */  | 
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| 93 | public function setData($data)  | 
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| 97 | |||
| 98 | /**  | 
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| 99 | * @return int  | 
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| 100 | */  | 
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| 101 | public function getVersion()  | 
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| 105 | |||
| 106 | /**  | 
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| 107 | * @param int $version  | 
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| 108 | */  | 
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| 109 | public function setVersion($version)  | 
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| 113 | |||
| 114 | /**  | 
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| 115 | * @return mixed  | 
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| 116 | */  | 
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| 117 | public function getTimeout()  | 
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| 125 | |||
| 126 | /**  | 
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| 127 | * @param mixed $timeout  | 
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| 128 | */  | 
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| 129 | public function setTimeout(DateTimeImmutable $timeout = null)  | 
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| 138 | |||
| 139 | /**  | 
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| 140 | * @return int  | 
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| 141 | */  | 
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| 142 | public function getDisabled()  | 
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| 146 | |||
| 147 | /**  | 
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| 148 | * @param int $disabled  | 
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| 149 | */  | 
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| 150 | public function setDisabled($disabled)  | 
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| 154 | |||
| 155 | /**  | 
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| 156 | * @return int  | 
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| 157 | */  | 
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| 158 | public function getPriority()  | 
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| 162 | |||
| 163 | /**  | 
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| 164 | * @param int $priority  | 
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| 165 | */  | 
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| 166 | public function setPriority($priority)  | 
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| 170 | |||
| 171 | View Code Duplication | public function save()  | 
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| 232 | }  | 
            
This check looks for the generic type
arrayas a return type and suggests a more specific type. This type is inferred from the actual code.