    def add_metric(self,
                   labels: Sequence[str],
                   value: float,
                   created: Optional[float] = None,
                   timestamp: Optional[Union[Timestamp, float]] = None,
                   exemplar: Optional[Exemplar] = None,
                   ) -> None:
        """Add a metric to the metric family.

        Args:
          labels: A list of label values
          value: The value of the metric
          created: Optional unix timestamp the child was created at.
        """
        self.samples.append(Sample(self.name + '_total', dict(zip(self._labelnames, labels)), value, timestamp, exemplar))
        if created is not None:
            self.samples.append(Sample(self.name + '_created', dict(zip(self._labelnames, labels)), created, timestamp))
Add a metric to the metric family.

Args:
labels: A list of label values
value: The value of the metric
created: Optional unix timestamp the child was created at.
prometheus_client/metrics_core.py