def METHOD_NAME(transition_model1, timestep):
    initial_state = State(np.array([[1]]), timestamp=datetime.datetime.now())
    simulator = SingleTargetGroundTruthSimulator(transition_model1,
                                                 initial_state, timestep)
    for step, (time, groundtruth_paths) in enumerate(simulator):
        # Check single ground truth track
        assert len(groundtruth_paths) == 1
        # Check length of path is equal to number of steps
        gt_path = groundtruth_paths.pop()
        assert len(gt_path) == step + 1
        # Check time is now + steps
        timedelta = simulator.timestep * step
        assert gt_path[-1].timestamp == initial_state.timestamp + timedelta
        # Check ground truth object has moved
        assert gt_path[-1].state_vector == initial_state.state_vector +\
            timedelta.total_seconds()
    # Check that the number of steps is equal to the simulation steps
    assert step + 1 == simulator.number_steps