'Assert that when called with unequal arguments, C{assertEqual} raises a
failure exception with the same message as the standard library
C{assertEqual} would have raised.'

def _testUnequalPair(self, first, second):

    raised = False
    try:
        self.assertEqual(first, second)
    except self.failureException as ourFailure:
        case = pyunit.TestCase('setUp')
        try:
            case.assertEqual(first, second)
        except case.failureException as theirFailure:
            raised = True
            got = str(ourFailure)
            expected = str(theirFailure)
            if (expected != got):
                self.fail(('Expected:    %r;    Got:    %r' % (expected, got)))
    if (not raised):
        self.fail(("Call    to    assertEqual(%r,    %r)    didn't    fail" % (first, second)))
