def __init__(self, metric, source):
    """
    Args:
      metric - The metric name.
      source - An optional source.
    """
    self._metric = metric
    self._source = source
    if self.VARZ_TYPE == VarzType.Gauge:
      self._fn = VarzReceiver.SetVarz
    elif self.VARZ_TYPE is (VarzType.AverageTimer, VarzType.AverageRate):
      self._fn = VarzReceiver.RecordPercentileSample
    else:
      self._fn = VarzReceiver.IncrementVarz

    if source:
      self._fn = functools.partial(self._fn, self._source)
    else:
      self._fn = self._Adapt(self._fn)
dataset/ETHPy150Open steveniemitz/scales/scales/varz.py/VarzMetric.__init__/operator `in` -> `is`