Return batch consisting of *consecutive* transitions

def get_trajectories(self, indexes, rollout_length):
        """ Return batch consisting of *consecutive* transitions """
        # assert indexes.shape[0] > 1, "There must be multiple indexes supplied"
        assert rollout_length > 1, "Rollout length must be greater than 1"

        batch_indexes = (
                indexes.reshape(1, indexes.shape[0]) - np.arange(rollout_length - 1, -1, -1).reshape(rollout_length, 1)
        )

        return self.get_transitions(batch_indexes)