code: def register_meterdict(self, name: str, meterdict: MeterDict) -> None:
      if "_meterdicts" not in self.__dict__:
          raise AttributeError(
              "cannot assign meterdict before MeterDict.__init__() call"
          )
      elif "/" in name:
          raise KeyError("meterdict name cannot contain '/'")
      elif name == "":
          raise KeyError("meterdict name cannot be empty")
      elif hasattr(self, name) and name not in self._meters:
          raise KeyError(f"attribute {name} already exists")
      self._meterdicts[name] = meterdict
  
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 3 for calling the MeterDict obj's underlying member method code with example usage: obj.register_meterdict(name, meterdict) without return types