code: def test_to_csv_with_dst_transitions_with_pickle(self):
      # GH11619
      idx = date_range(
          "2015-01-01", "2015-12-31", freq="h", tz="Europe/Paris"
      )
      idx = idx._with_freq(None)  # freq does not round-trip
      idx._data._freq = None  # otherwise there is trouble on unpickle
      df = DataFrame({"values": 1, "idx": idx}, index=idx)
      with tm.ensure_clean("csv_date_format_with_dst") as path:
          df.to_csv(path, index=True)
          result = read_csv(path, index_col=0)
          result.index = to_datetime(result.index, utc=True).tz_convert(
              "Europe/Paris"
          )
          result["idx"] = to_datetime(result["idx"], utc=True).astype(
              "datetime64[ns, Europe/Paris]"
          )
          tm.assert_frame_equal(result, df)
  
      # assert working
      df.astype(str)
  
      with tm.ensure_clean("csv_date_format_with_dst") as path:
          df.to_pickle(path)
          result = pd.read_pickle(path)
          tm.assert_frame_equal(result, df)
  
imports: import csv
  from io import StringIO
  import os
  import numpy
  import pytest
  from pandas.errors import ParserError
  import pandas
  from pandas import DataFrame, Index, MultiIndex, NaT, Series, Timestamp, date_range, period_range, read_csv, to_datetime
  import pandas._testing
  import pandas.core.common
  from pandas.io.common import get_handle
label_desc: Use image node_id 47 for calling the TestDataFrameToCSV obj's underlying member method code with example usage: obj.test_to_csv_with_dst_transitions_with_pickle() without return types