/**
  * Method that fetches and deletes document-file manyToMany association record Entity.
  *
  * @param  string $id file id
  * @return bool
  */
 protected function _deleteFileAssociationRecord($id)
 {
     $query = $this->_fileStorageAssociation->find('all', ['conditions' => [$this->_fileStorageForeignKey => $id]]);
     $entity = $query->first();
     if (is_null($entity)) {
         return false;
     }
     return $this->_fileStorageAssociation->delete($entity);
 }