def test_orderedFlagConstants_le(self):
        """
        L{twisted.python.constants.FlagConstant} preserves definition
        order in C{<=} comparisons.
        """
        self.assertTrue(PizzaToppings.mozzarella <= PizzaToppings.mozzarella)
        self.assertTrue(PizzaToppings.mozzarella <= PizzaToppings.pesto)
        self.assertTrue(PizzaToppings.pesto <= PizzaToppings.pepperoni)

        L{twisted.python.constants.FlagConstant} preserves definition
        order in C{<=} comparisons.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_constants.py