def _RemoveSink(self, endpoint):
    """Invoked when a node is removed from the underlying server set.

    If the node is currently active, it is removed from the aperture and replaced
    by an idle node (if one is available).  Otherwise, it is simply discarded.

    Args:
      endpoint - The endpoint being removed from the server set.
    """
    removed = super(ApertureBalancerSink, self)._RemoveSink(endpoint)
    if removed:
      self._TryExpandAperture()
    if self._idle_endpoints in endpoint:
      self._idle_endpoints.discard(endpoint)
    self._UpdateSizeVarz()
dataset/ETHPy150Open steveniemitz/scales/scales/loadbalancer/aperture.py/ApertureBalancerSink._RemoveSink/swapped operands of `in`