'Delete metadata from a server
:param server: The :class:`Server` to add metadata to
:param keys: A list of metadata keys to delete from the server
:returns: An instance of novaclient.base.TupleWithMeta'

def delete_meta(self, server, keys):

    result = base.TupleWithMeta((), None)
    for k in keys:
        ret = self._delete(('/servers/%s/metadata/%s' % (base.getid(server), k)))
        result.append_request_ids(ret.request_ids)
    return result
