def test_setTypes(self):
        """
        If the I{libc} object passed to L{initializeModule} has all of the
        necessary attributes, it sets the C{argtypes} and C{restype} attributes
        of the three ctypes methods used from libc.
        """
        class libc:
            def inotify_init(self):
                pass
            inotify_init = staticmethod(inotify_init)

            def inotify_rm_watch(self):
                pass
            inotify_rm_watch = staticmethod(inotify_rm_watch)

            def inotify_add_watch(self):
                pass
            inotify_add_watch = staticmethod(inotify_add_watch)

        c = libc()
        initializeModule(c)
        self.assertEqual(c.inotify_init.argtypes, [])
        self.assertEqual(c.inotify_init.restype, c_int)

        self.assertEqual(c.inotify_rm_watch.argtypes, [c_int, c_int])
        self.assertEqual(c.inotify_rm_watch.restype, c_int)

        self.assertEqual(
            c.inotify_add_watch.argtypes, [c_int, c_char_p, c_uint32])
        self.assertEqual(c.inotify_add_watch.restype, c_int)

        If the I{libc} object passed to L{initializeModule} has all of the
        necessary attributes, it sets the C{argtypes} and C{restype} attributes
        of the three ctypes methods used from libc.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/python/test/test_inotify.py