'``get_device_path`` raises ``UnknownVolume`` if the supplied
``blockdevice_id`` has not been created.'

def test_get_device_path_unknown_volume(self):

    unknown_blockdevice_id = self.unknown_blockdevice_id
    exception = self.assertRaises(UnknownVolume, self.api.get_device_path, unknown_blockdevice_id)
    self.assertEqual(unknown_blockdevice_id, exception.blockdevice_id)
