'Save all collections to disk'

def serialize(self):

    serializer.serialize(self._distros)
    serializer.serialize(self._repos)
    serializer.serialize(self._profiles)
    serializer.serialize(self._images)
    serializer.serialize(self._systems)
    serializer.serialize(self._mgmtclasses)
    serializer.serialize(self._packages)
    serializer.serialize(self._files)
