code: def test_whitespace_preservation():
      # see gh-16772
      header = None
      csv_data = """
   a ,bbb
   cc,dd """
  
      fwf_data = """
   a bbb
   ccdd """
      result = read_fwf(
          StringIO(fwf_data),
          widths=[3, 3],
          header=header,
          skiprows=[0],
          delimiter="\n\t",
      )
      expected = read_csv(StringIO(csv_data), header=header)
      tm.assert_frame_equal(result, expected)
  
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 30 for calling a global function with example usage: test_whitespace_preservation() without return types