| 1 | <?php | ||
| 24 | class Payone_Settings_Data_ConfigFile_PaymentMethod_Masterpass | ||
|  | |||
| 25 | extends Payone_Settings_Data_ConfigFile_PaymentMethod_Abstract | ||
| 26 | implements Payone_Settings_Data_ConfigFile_Interface | ||
| 27 | { | ||
| 28 | /** @var string */ | ||
| 29 | protected $key = Payone_Enum_ClearingType::MASTERPASS; | ||
| 30 | |||
| 31 | public function getKey() | ||
| 35 | } | 
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.