code: def test_dirty_colname_feature():
      df = pd.DataFrame(
          {
              "target :": [1],
              " my first feature:": ["x"],
              "white space at the end ": [2],
          }
      )
      features = [
          Feature(colname)
          for colname in [
              " my first feature:",
              "white space at the end ",
          ]
      ]
      conv = DFtoVW(
          label=SimpleLabel("target :"), features=features, df=df
      )
      first_line = conv.convert_df()[0]
      assert (
          first_line
          == "1 | my_first_feature=x white_space_at_the_end:2"
      )
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 11 for calling a global function with example usage: test_dirty_colname_feature() without return types