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 | ||
| 5 | class EcommerceMailchimpSignupMemberExtension extends DataExtension | ||
|  | |||
| 6 | { | ||
| 7 | private static $db = array( | ||
| 8 | 'SignedUpToMailchimp' => "Boolean" | ||
| 9 | ); | ||
| 10 | |||
| 11 | /** | ||
| 12 | * Store the user in MailChimp | ||
| 13 | * @param array $mergeVars | ||
| 14 | * @return Boolean | ||
| 15 | */ | ||
| 16 | public function subscribeToMailchimp($mergeVars = array()) | ||
| 42 | |||
| 43 | /** | ||
| 44 | * | ||
| 45 | * @return bool | ||
| 46 | */ | ||
| 47 | public function existsOnMailchimp() | ||
| 70 | |||
| 71 | /** | ||
| 72 | * | ||
| 73 | * @return bool | ||
| 74 | */ | ||
| 75 | public function updateOnMailchimp() | ||
| 98 | |||
| 99 | /** | ||
| 100 | * casted variable | ||
| 101 | */ | ||
| 102 | private static $_mailchimp_api = null; | ||
| 103 | |||
| 104 | /** | ||
| 105 | * @return MailChimp | ||
| 106 | */ | ||
| 107 | protected function getMailChimpAPI() | ||
| 117 | } | ||
| 118 | 
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.