code: def test_feature_column_renaming_and_tag():
      df = pd.DataFrame({"idx": ["id_1"], "y": [1], "x": [2]})
      conv = DFtoVW(
          label=SimpleLabel("y"),
          tag="idx",
          features=Feature(value="x", rename_feature="col_x"),
          df=df,
      )
      first_line = conv.convert_df()[0]
      assert first_line == "1 id_1| col_x:2"
  
imports: import pytest
  import pandas
  from vowpalwabbit.dftovw import ContextualbanditLabel, DFtoVW, Feature, MulticlassLabel, MultiLabel, Namespace, SimpleLabel
label_desc: Use image node_id 7 for calling a global function with example usage: test_feature_column_renaming_and_tag() without return types