code: protected function _pushError($field, $code, $title, $message = '')
      {
          $this->_errors[] = [
              'field'     => $field,
              'message'   => $message,
              'code'      => $code,
              'title'     => $title,
          ];
  
          return $this;
      }
docs: All error objects have field and code properties so that your client
  can tell what the problem is.
  
  If resources have custom validation errors, they should be documented
  with the resource.
  
  @param string $field The erroneous field or column
  @param string $code One of the ERR_* codes contants
  @param string $title A title for this error
  @param string $message A friendly message
  @return Benri_Db_Table_Row