code: def time_tz_convert(self, tz):
      if self.ts.tz is not None:
          self.ts.tz_convert(tz)
  
imports: from datetime import datetime
  import numpy
  import pytz
  from pandas import Timestamp
  from .tslib import _tzs
label_desc: Use image node_id 6 for calling the TimestampOps obj's underlying member method code with example usage: obj.time_tz_convert(tz) without return types