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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| 17 | View Code Duplication | class PostCommandEvent extends Event  | 
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| 18 | { | 
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| 19 | /** @var CommandInterface */  | 
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| 20 | private $command;  | 
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| 21 | |||
| 22 | /** @var ResponseInterface */  | 
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| 23 | private $response;  | 
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| 24 | |||
| 25 | /**  | 
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| 26 | *  | 
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| 27 | * @param CommandInterface $command  | 
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| 28 | * @param ResponseInterface $response  | 
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| 29 | */  | 
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| 30 | public function __construct(CommandInterface $command, ResponseInterface $response)  | 
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| 35 | |||
| 36 | /**  | 
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| 37 | *  | 
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| 38 | * @return CommandInterface  | 
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| 39 | */  | 
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| 40 | public function getCommand()  | 
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| 44 | |||
| 45 | /**  | 
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| 46 | *  | 
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| 47 | * @return ResponseInterface  | 
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| 48 | */  | 
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| 49 | public function getResponse()  | 
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| 53 | }  | 
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| 54 |