code: def __str__(self):
      return self.zone
  
imports: from datetime import datetime, timedelta, tzinfo
  from bisect import bisect_right
  import pytz
  from pytz.exceptions import AmbiguousTimeError, NonExistentTimeError
label_desc: Use image node_id 1 for calling the BaseTzInfo obj's underlying member method code with example usage: obj.__str__() and returns: self