Update AbstractExtensibleModel.php

Author: atwixfirster

lib/internal/Magento/Framework/Model/AbstractExtensibleModel.php

@@ -15,8 +15,8 @@
  * This class defines basic data structure of how custom attributes are stored in an ExtensibleModel.
  * Implementations may choose to process custom attributes as their persistence requires them to.
  * @SuppressWarnings(PHPMD.NumberOfChildren)
+ * phpcs:disable Magento2.Classes.AbstractApi
  * @api
- * @codeCoverageIgnore
  */
 abstract class AbstractExtensibleModel extends AbstractModel implements
     \Magento\Framework\Api\CustomAttributesDataInterface