docstr: Get token expiration time. If not present, assume forever 
docstr_tok: ["Get","token","expiration","time",".","If","not","present",",","assume","forever"]
code: def _get_token_exp(cls, token):
      """Get token expiration time. If not present, assume forever"""
      return cls.get_decoded_token(token).get("exp", sys.maxsize)
  
imports: import sys
  from abc import ABCMeta, abstractmethod
  from time import time
  import jwt
  from jwt.algorithms import get_default_algorithms
  import six
label_desc: Use image node_id 11 for calling the TokenManager obj's underlying member method code with example usage: obj._get_token_exp(cls, token) and returns: cls