'A L{failure.Failure} constructed from another
L{failure.Failure} instance, has its C{value} property set to
the value of that L{failure.Failure} instance.'

def test_failureValueFromFailure(self):

    exception = ValueError()
    f1 = failure.Failure(exception)
    f2 = failure.Failure(f1)
    self.assertIs(f2.value, exception)
