@classmethod
  def wait_any(cls, futures):
    # TODO: Flatten MultiRpcs.
    waiting_on = set(futures)
    ev = eventloop.get_event_loop()
    while waiting_on:
      for f in waiting_on:
        if f.state is cls.FINISHING:
          return f
      ev.run1()
    return None

  # TODO: Have a tasklet that does this
dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/ext/ndb/tasklets.py/Future.wait_any/operator `==` -> `is`