code: def _named_meters(self, prefix: str = ""):
      memo = set()
      for name_prefix, meterdict in self._named_dicts(prefix=prefix):
          for name, meter in meterdict._meters.items():
              if meter in memo:
                  continue
              memo.add(meter)
              name = (
                  name_prefix
                  + ("/" if len(name_prefix) > 0 else "")
                  + name
              )
              yield name, meter
  
imports: from __future__ import annotations
  import warnings
  import json
  from typing import Dict, Union, Optional
  from collections import OrderedDict
  from .meters import Meter
label_desc: Use image node_id 12 for calling the MeterDict obj's underlying member method code with example usage: obj._named_meters(prefix) without return types