def METHOD_NAME(self, block, root=False):
    if not isinstance(block, dict):
        return ()
    bid = None
    refs = set()
    for k, v in list(block.items()):
        if k == "id":
            bid = v
            self._id_map[v] = block
        elif isinstance(v, str) and self.is_id_ref(v):
            refs.add(v)
        if isinstance(v, (str, int, float, bool)):
            continue
        if isinstance(v, dict) and k != "__tfmeta":
            refs.update(self.METHOD_NAME(v))
        if isinstance(v, list):
            list(map(self.METHOD_NAME, v))
    if refs and block.get("__tfmeta", {}).get("label"):
        self._ref_map.setdefault(bid, []).extend(refs)
        for r in refs:
            self._ref_map.setdefault(r, []).append(bid)
    return refs