def __invariant__(self):
        manifestations = self.manifestations.values()
        for app in self.applications:
            if app.volume is not None:
                if app.volume.manifestation not in manifestations:
                    return (False, '%r manifestation is not on node' % (app,))
        return (True, "")
dataset/ETHPy150Open ClusterHQ/flocker/flocker/control/_model.py/Node.__invariant__/original