def test_contains(self):
        prio_set_list = event._PrioritizedSetList()
        obj = object()

        prio_set_list.add(0, obj)
        assert obj in prio_set_list
def __init__(self, gan=None, config=None, trainer=None):
      super().__init__(config=config, gan=gan, trainer=trainer)
      self.d_grads = None
      self.g_grads = None