code: def test_astimezone(self, tzstr):
      # astimezone is an alias for tz_convert, so keep it with
      # the tz_convert tests
      utcdate = Timestamp("3/11/2012 22:00", tz="UTC")
      expected = utcdate.tz_convert(tzstr)
      result = utcdate.astimezone(tzstr)
      assert expected == result
      assert isinstance(result, Timestamp)
  
file_path: pandas/pandas/tests/scalar/timestamp/methods/test_tz_convert.py
imports: import dateutil
  import pytest
  from pandas._libs.tslibs import timezones
  import pandas.util._test_decorators
  from pandas import Timestamp
label_desc: Use image node_id 1 for calling the TestTimestampTZConvert obj's underlying member method code with example usage: obj.test_astimezone(tzstr) without return types