def test_invalid_url():
    """
    Given an invalid URL, when url() is called with the URL, then it raises
    ValueError.
    """
    with pytest.raises(ValueError):
        mod.url('this is an invalid URL')
def test_invalid_url():
    """
    Given an invalid URL, when url() is called with the URL, then it raises
    ValueError.
    """
    with pytest.raises(ValueError):
        mod.url("this is an invalid URL")
def test_url(x):
    """
    Given a valid URL, when url() is called with the URL, then it returns the
    URL.
    """
    assert mod.url(x) == x
def test_url(x):
    """
    Given a valid URL, when url() is called with the URL, then it returns the
    URL.
    """
    assert mod.url(x) == x