def METHOD_NAME(self):
    state = TraceState([("a", "1"), ("b", "2"), ("c", "3")])
    new_state = state.delete("b")
    self.assertIsNone(new_state.get("b"))
    entries = list(new_state.items())
    a_place = entries.index(("a", "1"))
    c_place = entries.index(("c", "3"))
    self.assertLessEqual(a_place, c_place)