code: def _is_container_metric(labels):
          
          for lbl in CONTAINER_LABELS:
              if lbl == 'container_name':
                  if lbl in labels:
                      if labels[lbl] == '' or labels[lbl] == 'POD':
                          return False
              if lbl not in labels:
                  return False
          return True
docs: Return whether a metric is about a container or not.
          It can be about pods, or even higher levels in the cgroup hierarchy
          and we don't want to report on that.
          :param metric:
          :return: bool