code: def test_binary_mode():
      """
      read_fwf supports opening files in binary mode.
  
      GH 18035.
      """
      data = """aaa aaa aaa
  bba bab b a"""
      df_reference = DataFrame(
          [["bba", "bab", "b a"]],
          columns=["aaa", "aaa.1", "aaa.2"],
          index=[0],
      )
      with tm.ensure_clean() as path:
          Path(path).write_text(data, encoding="utf-8")
          with open(path, "rb") as file:
              df = read_fwf(file)
              file.seek(0)
              tm.assert_frame_equal(df, df_reference)
  
imports: from datetime import datetime
  from io import BytesIO, StringIO
  from pathlib import Path
  import numpy
  import pytest
  from pandas.errors import EmptyDataError
  import pandas
  from pandas import DataFrame, DatetimeIndex
  import pandas._testing
  from pandas.core.arrays import ArrowStringArray, StringArray
  from pandas.io.common import urlopen
  from pandas.io.parsers import read_csv, read_fwf
label_desc: Use image node_id 33 for calling a global function with example usage: test_binary_mode() without return types