code: private function checkReadOnly()
      {
          if (true === $this->_readOnly) {
              $this->_pushError(
                  '',
                  self::ERR_READ_ONLY,
                  'This row has been marked read-only'
              );
  
              return false;
          }
  
          return true;
      }
docs: Check if this model is set as a read-only model.
  
  @return bool