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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| 7 | class SlugTest extends PHPUnit_Framework_TestCase  | 
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| 8 | { | 
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| 9 | /**  | 
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| 10 | * If the given Slug is valid validateSlug should not throw an exception  | 
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| 11 | *  | 
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| 12 | * @test  | 
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| 13 | * @dataProvider getValidSlugs  | 
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| 14 | *  | 
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| 15 | * @param string $sku A Slug  | 
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| 16 | */  | 
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| 17 | View Code Duplication | public function validateSlug_validSlugs_NoExceptionIsThrown($sku)  | 
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| 33 | |||
| 34 | /**  | 
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| 35 | * If the given Slug is invalid validateSlug should throw an exception  | 
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| 36 | *  | 
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| 37 | * @test  | 
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| 38 | * @dataProvider getInvalidSlugs  | 
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| 39 | *  | 
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| 40 | * @param string $sku A Slug  | 
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| 41 | * @param string $expectedExceptionMessage The expected exception message  | 
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| 42 | */  | 
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| 43 | View Code Duplication | public function validateSlug_invalidSlugs_ExceptionIsThrown($sku, $expectedExceptionMessage)  | 
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| 64 | |||
| 65 | /**  | 
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| 66 | * Get a list of valid Slugs  | 
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| 67 | *  | 
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| 68 | * @return array  | 
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| 69 | */  | 
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| 70 | public static function getValidSlugs()  | 
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| 97 | |||
| 98 | /**  | 
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| 99 | * Get a list of invalid Slugs  | 
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| 100 | *  | 
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| 101 | * @return array  | 
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| 102 | */  | 
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| 103 | public static function getInvalidSlugs()  | 
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| 132 | }  | 
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| 133 | 
You can fix this by adding a namespace to your class:
When choosing a vendor namespace, try to pick something that is not too generic to avoid conflicts with other libraries.