View difference between Paste ID: 6hTw5WDC and i6Nj7CD2

 from twisted.trial.unittest import TestCase
 from twisted.protocols.amp import (
     Command, Integer, CommandLocator, BoxDispatcher, COMMAND, ASK, ANSWER)
 
 ################### Application code ###################
 
 
 class Sum(Command):
 
     arguments = [("a", Integer()), ("b", Integer())]
     response = [("result", Integer())]
 
 
 class Math(CommandLocator):
 
     @Sum.responder
     def sum(self, a, b):
         return {"result": a + b}
 
 
 class MathClient(object):
     """This is an example of application client code using C{callRemote}.
 
     It just provides a convenient abstraction around the application-defined
     AMP commands.
     """
 
     def __init__(self, protocol):
         """
         @param protocol: An C{AMP} instance connected to a remote L{Math}
             command locator.
         """
         self._protocol = protocol
 
     def sum(self, a, b):
         deferred = self._protocol.callRemote(Sum, a=a, b=b)
         return deferred.addCallback(lambda response: response["result"])
 
 
 ################### Application tests ###################
 
 
 class FakeBoxSender(object):
 
     def __init__(self):
         self.sent = []
 
     def sendBox(self, box):
         self.sent.append(box)
 
 
 class MathTest(TestCase):
 
     def setUp(self):
         super(MathTest, self).setUp()
-        self.locator = Math()
+
-        self.dispatcher = BoxDispatcher(self.locator)
+        self.dispatcher = BoxDispatcher(locator)
         self.sender = FakeBoxSender()
         self.dispatcher.startReceivingBoxes(self.sender)
 
     def test_sum_request(self):
         """
         This is mainly a wiring test, asserting that L{Math.sum} is decorated
         with @Sum.responder.
 
         Incidentally it also exercises L{Sum.arguments} and implies that the
         'a' and 'b' arguments are deserialized to C{int}s.
 
         One would ideally also test the L{Method.sum} on its own directly, by
         instantiating the L{Math} class, and really exercising all its actual
         logic.
         """
         box = {COMMAND: "Sum", ASK: "1", "a": "3", "b": "2"}
         self.dispatcher.ampBoxReceived(box)
         self.assertEqual(self.sender.sent, [{ANSWER: "1", "result": "5"}])
 
     def test_sum_response(self):
         """
         Maybe there should be a test for exercising L{Sum.response} too?
 
         It would directly or indirectly, make sure that the 'result' field is
         deserialized to C{int}.
         """
 
 
 class FakeBoxDispatcher(object):
 
     def __init__(self, locator):
         self.locator = locator
 
     def callRemote(self, commandType, *a, **kw):
         """
         Faking C{callRemote} this way is slightly unfortunate because it
         duplicates the real AMP logic a bit, but it might acceptable.
         """
         responder = self.locator.locateResponder(commandType.commandName)
         deferred = responder(kw)
         return deferred.addCallback(commandType.parseResponse, self)
 
 
 class MathClientTest(TestCase):
 
     def setUp(self):
         super(MathClientTest, self).setUp()
         locator = Math()
         dispatcher = FakeBoxDispatcher(locator)
         self.client = MathClient(dispatcher)
 
     def test_sum(self):
         """
         This tests L{MathClient}, and it does so by running a real L{Math}
         command locator, except that there is no network/transport involved.
 
         Other layers of the application code using L{MathClient} could as well
         have their tests setup using a real L{MatchClient} instantiated with
         a L{FakeBoxDispatcher} as well, as opposed to creating fake versions
         of L{MathClient}.
 
         This would of course make such higher-layer tests more "integration"
         and less "unit", but in practice it might be more convenient and
         give more confidence that mocking out L{MathClient} (drifting to
         state-based vs. behavior-based testing here, sorry).
         """
         deferred = self.client.sum(3, 2)
         self.assertEqual(5, self.successResultOf(deferred))