'Test L{ftp.FTPClient.cdup}\'s handling of a failed CDUP command.
When the CDUP command fails, the returned Deferred should errback
with L{ftp.CommandFailed}.'

def test_failedCDUP(self):

    self._testLogin()
    d = self.client.cdup()
    self.assertFailure(d, ftp.CommandFailed)
    self.assertEqual(self.transport.value(), 'CDUP\r\n')
    self.transport.clear()
    self.client.lineReceived('550    ..:    No    such    file    or    directory')
    return d
