'If the wrapped C{Exception} is not a subclass of one of the
expected types, L{failure.Failure.trap} raises the wrapped
C{Exception}.'

def test_trapRaisesWrappedException(self):

    exception = ValueError()
    try:
        raise exception
    except:
        f = failure.Failure()
    untrapped = self.assertRaises(ValueError, f.trap, OverflowError)
    self.assertIs(exception, untrapped)
