code: def test_stubs(self):
      # GH9204 wide_to_long call should not modify 'stubs' list
      df = DataFrame([[0, 1, 2, 3, 8], [4, 5, 6, 7, 9]])
      df.columns = ["id", "inc1", "inc2", "edu1", "edu2"]
      stubs = ["inc", "edu"]
  
      wide_to_long(df, stubs, i="id", j="age")
  
      assert stubs == ["inc", "edu"]
  
imports: import re
  import numpy
  import pytest
  import pandas
  from pandas import DataFrame, Index, date_range, lreshape, melt, wide_to_long
  import pandas._testing
label_desc: Use image node_id 2 for calling the TestWideToLong obj's underlying member method code with example usage: obj.test_stubs() without return types