def METHOD_NAME():
    test_dataframe = DataFrame({"foo": ["foo", "bar", "baz"]})
    assert UniqueColumnConstraint(ignore_missing_vals=False).validate(test_dataframe, "foo") is None
    bad_test_dataframe = DataFrame({"foo": ["foo", "foo", "baz"]})
    with pytest.raises(ConstraintViolationException):
        UniqueColumnConstraint(ignore_missing_vals=False).validate(bad_test_dataframe, "foo")