'``set_maximum_size`` results in the associated filesystem having a
new maximum size quota applied according to the given ``Volume``.'

def test_set_maximum_size_applied(self):

    pool = FilesystemStoragePool(FilePath(self.mktemp()))
    service = VolumeService(FilePath(self.mktemp()), pool, reactor=Clock())
    service.startService()
    d = service.create(service.get(MY_VOLUME))
    created_volume = self.successResultOf(d)
    created_fs = pool.get(created_volume)
    volume_size = VolumeSize(maximum_size=((1024 * 1024) * 10))
    d = service.set_maximum_size(service.get(MY_VOLUME, size=volume_size))
    resized_volume = self.successResultOf(d)
    resized_fs = pool.get(resized_volume)
    self.assertEqual(created_fs.size, VolumeSize(maximum_size=None))
    self.assertEqual(resized_volume.size, resized_fs.size)
