docs: def WriteFlowResults(self, results):
      """Writes flow results for a given flow."""
      for r in results:
        dest = self.flow_results.setdefault((r.client_id, r.flow_id), [])
        to_write = r.Copy()
        to_write.timestamp = rdfvalue.RDFDatetime.Now()
        dest.append(to_write)