code: def time_tz_localize(self, tz):
      if self.ts.tz is None:
          self.ts.tz_localize(tz)
  
imports: from datetime import datetime
  import numpy
  import pytz
  from pandas import Timestamp
  from .tslib import _tzs
label_desc: Use image node_id 7 for calling the TimestampOps obj's underlying member method code with example usage: obj.time_tz_localize(tz) without return types