def test_handle_feature_1dim():
    """
    1-dimensional arrays are converted to 2-dimensional column vectors.
    """
    array = np.array([1, 2])
    assert_array_equal(_handle_feature(array), np.array([[1], [2]]))
def test_handle_feature_2dim():
    """
    2-dimensional arrays are returned unchanged.
    """
    array = np.array([[1, 2], [3, 4]])
    assert_array_equal(_handle_feature(array), array)