code: def is_token_expired(self, offset=0):
          
          if self.token_expiry is None:
              return True
          return int(time.time()) >= (self.token_expiry - offset)
docs: Return true if the token is expired.
  
          The offset can be used to change the expiry time:
          - positive value decrease the time (sooner)
          - negative value increase the time (later)
          If the expiry is not set, always return True. This case allow the users
          to define a security object, only knowing the refresh_token and get
          a new access_token / expiry_time without errors.
  
          :param offset: the expiry offset (in seconds) [default: 0]
          :return: boolean true if expired, else false.