class_docstr: Metaclass to make a metaclassed class a singleton
class_docstr_tok: ["Metaclass","to","make","a","metaclassed","class","a","singleton"]
code: def __init__(cls, name, bases, dct):
      super(MetaSingleton, cls).__init__(name, bases, dct)
      cls._singleton = None
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import collections
  from datetime import datetime, timedelta
  import time
  import json
  import threading
  import oandapy
  import requests
  import backtrader
  from backtrader.metabase import MetaParams
  from backtrader.utils.py3 import queue, with_metaclass
  from backtrader.utils import AutoDict
label_desc: Use image node_id 1 to create a new MetaSingleton object from inherited base classes: MetaParams with example: obj = MetaSingleton(cls, name, bases, dct)