def get_input_space(cls):
        """
       The Input space is a class attribute
       """
        engine_global_config = get_global_config()
        assert engine_global_config["discrete_action"]
        discrete_throttle_dim = engine_global_config["discrete_throttle_dim"]
        use_multi_discrete = engine_global_config["use_multi_discrete"]
        discrete_steering_dim = 3

        if use_multi_discrete:
            return gym.spaces.MultiDiscrete([discrete_steering_dim, discrete_throttle_dim])
        else:
            return gym.spaces.Discrete(discrete_steering_dim * discrete_throttle_dim)

       The Input space is a class attribute
       
metadrive/policy/lange_change_policy.py