def METHOD_NAME():
    existing = {"foo": "bar"}
    initial_existing = existing.copy()
    assert set(MergeBehavior) == {
        MergeBehavior.Append,
        MergeBehavior.Update,
        MergeBehavior.Clobber,
        MergeBehavior.DictKeyAppend,
    }
    for behavior in MergeBehavior:
        assert behavior.meta() == {"merge": behavior}
        assert behavior.meta(existing) == {"merge": behavior, "foo": "bar"}
        assert existing == initial_existing