code: def _execute(self, ifile, process):
          
          if self._protocol_version == 2:
              result = self._read_chunk(ifile)
  
              if not result:
                  return
  
              metadata, body = result
              action = getattr(metadata, 'action', None)
  
              if action != 'execute':
                  raise RuntimeError('Expected execute action, not {}'.format(action))
  
          self._record_writer.write_records(self.generate())
          self.finish()
docs: Execution loop
  
          :param ifile: Input file object. Unused.
          :type ifile: file
  
          :return: `None`.