'Test that each isTypeTk calls _init_tk_type when _tk_type is None.'

@mock.patch('idlelib.macosx._init_tk_type')
def test_is_calls_init(self, mockinit):

    macosx._tk_type = None
    for (func, whentrue) in self.isfuncs:
        with self.subTest(func=func):
            func()
            self.assertTrue(mockinit.called)
            mockinit.reset_mock()
