def test_value_transform():
    """
    **Overview**:
        Generate fake data and test the ``value_transform`` and ``value_inv_transform`` functions.
    """
    # Generate fake data.
    test_x = torch.randn(10)
    # Normalize the generated data.
    normalized_x = value_transform(test_x)
    assert normalized_x.shape == (10,)
    # Unnormalize the data.
    unnormalized_x = value_inv_transform(normalized_x)
    # Test whether the data before and after the transformation is the same.
    assert torch.sum(torch.abs(test_x - unnormalized_x)) < 1e-3

    **Overview**:
        Generate fake data and test the ``value_transform`` and ``value_inv_transform`` functions.
    
chapter4_reward/value_rescale.py