code: def dst(self, dt):
      if self._isdst(dt):
          return DSTDIFF
      else:
          return ZERO
  
imports: from __future__ import absolute_import, division, print_function, unicode_literals
  import datetime
  import math
  import time
  from .py3 import string_types
label_desc: Use image node_id 2 for calling the _LocalTimezone obj's underlying member method code with example usage: obj.dst(dt) and returns: DSTDIFF, ZERO