class_docstr: Metaclass that creates a Singleton instance.
class_docstr_tok: ["Metaclass","that","creates","a","Singleton","instance","."]
code: def __call__(cls, *args, **kwargs):
      with cls._lock:
          if cls not in cls._instances:
              instance = super().__call__(*args, **kwargs)
              cls._instances[cls] = instance
          else:
              cls._instances[cls]._set_session(*args, **kwargs)
          return cls._instances[cls]
  
imports: import functools
  from functools import lru_cache
  import requests
  from bs4 import BeautifulSoup
  import datetime
  from frozendict import frozendict
  from .None import utils, cache
  import threading
label_desc: Use image node_id 1 for calling the SingletonMeta obj's underlying member method code with example usage: obj.__call__(cls) and returns: cls