/**
  * Override to remove any valuesToParentValues where the attributeName is null.
  * @see AttributeForm::sanitizeFromPostAndSetAttributes()
  */
 public function sanitizeFromPostAndSetAttributes($values)
 {
     assert('is_array($values)');
     if (isset($values['mappingData'])) {
         foreach ($values['mappingData'] as $position => $data) {
             if ($data['attributeName'] == null && isset($data['valuesToParentValues'])) {
                 unset($values['mappingData'][$position]['valuesToParentValues']);
             }
         }
     }
     parent::sanitizeFromPostAndSetAttributes($values);
 }