code: protected function verifyData()
      {
          if (isset($this->_DATA_TYPE) || !empty($this->_DATA_TYPE)) {
              $this->verifyDataType();
          }
          if (!empty($this->_REQUIRED_DATA)) {
              $this->verifyRequiredData();
          }
          return true;
      }
docs: Validate the Data property on the Endpoint
  @return bool
  @throws RequiredDataException