code: def test_df_getitem():
      df = DataFrame({"foo": (1, 1, 3), "bar": (4, 5, 6)})
  
      getitem = df["foo"]
      required_columns = SelfColumnSelector.select(getitem.data)
      assert required_columns == {"foo"}
  
      getitem = df[["foo", "bar"]]
      required_columns = SelfColumnSelector.select(getitem.data)
      assert required_columns == {"foo", "bar"}
  
imports: from ......dataframe import DataFrame
  from ..self_column_selector import SelfColumnSelector
label_desc: Use image node_id 2 for calling a global function with example usage: test_df_getitem() without return types