code: def record(self, tags, measurement_map, timestamp, attachments=None):
          
          assert all(vv >= 0 for vv in measurement_map.values())
          for measure, value in measurement_map.items():
              if measure != self._registered_measures.get(measure.name):
                  return
              view_datas = []
              for measure_name, view_data_list \
                      in self._measure_to_view_data_list_map.items():
                  if measure_name == measure.name:
                      view_datas.extend(view_data_list)
              for view_data in view_datas:
                  view_data.record(
                      context=tags, value=value, timestamp=timestamp,
                      attachments=attachments)
              self.export(view_datas)
docs: records stats with a set of tags