class_docstr: A convenient vocab container that can store multiple BaseVocab instances, and support 
  safe serialization of all instances via state dicts. Each subclass of this base class 
  should implement the load_state_dict() function to specify how a saved state dict 
  should be loaded back.
docstr: Construct a MultiVocab by reading from a state dict.
docstr_tok: ["Construct","a","MultiVocab","by","reading","from","a","state","dict","."]
code: def load_state_dict(cls, state_dict):
      """Construct a MultiVocab by reading from a state dict."""
      raise NotImplementedError
  
imports: from copy import copy
  from collections import Counter, OrderedDict
  from collections.abc import Iterable
  import os
  import pickle
label_desc: Use image node_id 8 for calling the BaseMultiVocab obj's underlying member method code with example usage: obj.load_state_dict(cls, state_dict) without return types