'When the checker specified by --auth raises an unexpected error, it
should be caught and re-raised within a L{usage.UsageError}.'

def test_unexpectedException(self):

    options = DummyOptions()
    err = self.assertRaises(usage.UsageError, options.parseOptions, ['--auth', 'file'])
    self.assertEqual(str(err), "Unexpected    error:    'file'    requires    a    filename")
