code: def data(self, data=None, ret_r=False):
          '''response data'''
          if data or ret_r:
              self._data = data
              return self
          return self._datf data(self, data=None, ret_r=False):
          '''response data'''
          if data or ret_r:
              self._data = data
              return self
          return self._data
docs: response data