/**
  * Gets a service definition.
  *
  * @param string $id The service identifier
  *
  * @return tubepress_api_ioc_DefinitionInterface A tubepress_api_ioc_DefinitionInterface instance, or null if the
  *                                               service does not exist.
  *
  * @api
  * @since                                        3.1.0
  */
 public function getDefinition($id)
 {
     try {
         /**
          * @var $fromDelegate tubepress_impl_ioc_IconicDefinitionWrapper
          */
         $fromDelegate = $this->_delegate->getDefinition($id);
         return $this->_callbackConvertToTubePressDefinition($fromDelegate);
     } catch (ehough_iconic_exception_InvalidArgumentException $e) {
         return null;
     }
 }