'Resize an existing volume.
:param Volume volume: The ``Volume`` instance to resize in the storage
pool.
:return: A ``Deferred`` that fires with a :class:`Volume`.'

def set_maximum_size(self, volume):

    d = self.pool.set_maximum_size(volume)
    def resized(filesystem):
        return volume
    d.addCallback(resized)
    return d
