code: def test_to_csv_stdout_file(self, capsys):
      # GH 21561
      df = DataFrame(
          [["foo", "bar"], ["baz", "qux"]], columns=["name_1", "name_2"]
      )
      expected_rows = [",name_1,name_2", "0,foo,bar", "1,baz,qux"]
      expected_ascii = tm.convert_rows_list_to_csv_str(expected_rows)
  
      df.to_csv(sys.stdout, encoding="ascii")
      captured = capsys.readouterr()
  
      assert captured.out == expected_ascii
      assert not sys.stdout.closed
  
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 22 for calling the TestToCSV obj's underlying member method code with example usage: obj.test_to_csv_stdout_file(capsys) without return types