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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| 20 | class GuzzleAdapter implements AdapterInterface  | 
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| 21 | { | 
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| 22 | /**  | 
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| 23 | * Guzzle client  | 
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| 24 | *  | 
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| 25 | * @var Client  | 
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| 26 | */  | 
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| 27 | private $client;  | 
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| 28 | |||
| 29 | /**  | 
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| 30 | * curl options  | 
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| 31 | *  | 
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| 32 | * @var array  | 
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| 33 | */  | 
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| 34 | private $options;  | 
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| 35 | |||
| 36 | |||
| 37 | /**  | 
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| 38 | * GuzzleAdapter constructor.  | 
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| 39 | *  | 
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| 40 | * @link https://gist.github.com/jseidl/3218673  | 
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| 41 | *  | 
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| 42 | * @param Client $client guzzle client  | 
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| 43 | * @param array $curlOptions List of curl options to be recognized for a request.  | 
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| 44 | */  | 
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| 45 | public function __construct(Client $client, array $curlOptions)  | 
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| 50 | |||
| 51 | /**  | 
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| 52 | * @inheritDoc  | 
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| 53 | *  | 
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| 54 | * @param RequestInterface $request request  | 
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| 55 | *  | 
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| 56 | * @return ResponseInterface  | 
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| 57 | */  | 
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| 58 | public function send(RequestInterface $request)  | 
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| 62 | |||
| 63 | /**  | 
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| 64 | * @param string $method  | 
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| 65 | * @param string $uri  | 
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| 66 | * @param array $options  | 
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| 67 | *  | 
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| 68 | * @return mixed|ResponseInterface  | 
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| 69 | */  | 
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| 70 | public function request($method, $uri = '', array $options = [])  | 
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| 77 | |||
| 78 | /**  | 
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| 79 | * @return array  | 
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| 80 | */  | 
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| 81 | private function applyOptions($options)  | 
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| 91 | |||
| 92 | |||
| 93 | }  | 
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| 94 | 
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.