def METHOD_NAME(self):
    # Can also use simple datatypes as argument type specifiers
    # for the callback function.
    # In this case the call receives an instance of that type
    f = dll._testfunc_callback_i_if
    f.restype = c_int
    MyCallback = CFUNCTYPE(c_int, c_int)
    f.argtypes = [c_int, MyCallback]
    def callback(value):
        #print "called back with", value
        self.assertEqual(type(value), int)
        return value
    cb = MyCallback(callback)
    result = f(self.wrap(-10), self.wrap(cb))
    self.assertEqual(result, -18)