def add_metric(self, labels, count_value, sum_value, timestamp=None):
self.samples.append(Sample(self.name + '<STR_LIT>', dict(zip(self._labelnames, labels)), count_value, timestamp))<EOL>self.samples.append(Sample(self.name + '<STR_LIT>', dict(zip(self._labelnames, labels)), sum_value, timestamp))<EOL>
Add a metric to the metric family.

        Args:
          labels: A list of label values
          count_value: The count value of the metric.
          sum_value: The sum value of the metric.