def test_non_callable(self):
        with pytest.raises(TypeError) as excinfo:
            event.event(123)
        excinfo.match(r"Expected string, callable or None as first argument")

        with pytest.raises(TypeError) as excinfo:
            event.event("name")([])
        excinfo.match(r"Callable must be a function \(`def`\)"
                      r" or coroutine function \(`async def`\)")
def test_emtpy(self):
        # I had problems with these
        #
        # Although these are patological cases: Empty Structures!
        class X(Structure):
            _fields_ = []

        class Y(Union):
            _fields_ = []

        # Is this really the correct alignment, or should it be 0?
        self.assertTrue(alignment(X) == alignment(Y) == 1)
        self.assertTrue(sizeof(X) == sizeof(Y) == 0)

        class XX(Structure):
            _fields_ = [("a", X),
                        ("b", X)]

        self.assertEqual(alignment(XX), 1)
        self.assertEqual(sizeof(XX), 0)