'``enumerate()`` returns no volumes when there are no volumes.'

def test_enumerate_no_volumes(self):

    pool = FilesystemStoragePool(FilePath(self.mktemp()))
    service = VolumeService(FilePath(self.mktemp()), pool, reactor=Clock())
    service.startService()
    volumes = self.successResultOf(service.enumerate())
    self.assertEqual([], list(volumes))
