code: def add_metric_values(self, values):
          
          assert isinstance(values, FakedMetricObjectValues)
          group_name = values.group_name
          if group_name not in self._metric_values:
              self._metric_values[group_name] = []
          self._metric_values[group_name].append(values)
          if group_name not in self._metric_value_names:
              self._metric_value_names.append(group_name)
docs: Add one set of faked metric values for a particular resource to the
          metrics response for a particular metric group, for later retrieval.
  
          For defined metric groups, see chapter "Metric groups" in the
          :term:`HMC API` book.
  
          Parameters:
  
            values (:class:`~zhmclient.FakedMetricObjectValues`):
              The set of metric values to be added. It specifies the resource URI
              and the targeted metric group name.