def METHOD_NAME(self):
    s = utils.FixedParameters()
    self.assertEqual(len(s), 0, "initial set is empty")
    s.add_or_discard("a", True)
    self.assertEqual(len(s), 1, "a is in set")
    s.add_or_discard("a", None)
    self.assertEqual(len(s), 1, "set is untouched")
    s.add_or_discard("a", False)
    self.assertEqual(len(s), 0, "set is empty again")
    s.add_or_discard("a", None)
    self.assertEqual(len(s), 0, "set is untouched")
    s.add_or_discard("a", False)
    self.assertEqual(len(s), 0, "set is still empty")