code: def test_to_csv_write_to_open_file_with_newline_py3(self):
      # see gh-21696
      # see gh-20353
      df = DataFrame({"a": ["x", "y", "z"]})
      expected_rows = ["x", "y", "z"]
      expected = "manual header\n" + tm.convert_rows_list_to_csv_str(
          expected_rows
      )
      with tm.ensure_clean("test.txt") as path:
          with open(path, "w", newline="", encoding="utf-8") as f:
              f.write("manual header\n")
              df.to_csv(f, header=None, index=None)
  
          with open(path, "rb") as f:
              assert f.read() == bytes(expected, "utf-8")
  
imports: import io
  import os
  import sys
  from zipfile import ZipFile
  from _csv import Error
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, compat
  import pandas._testing
label_desc: Use image node_id 24 for calling the TestToCSV obj's underlying member method code with example usage: obj.test_to_csv_write_to_open_file_with_newline_py3() without return types