code: def test_confirm_variables(df_vartypes):
      variables = ["banana", "manzana", "Name", "Age"]
      tr = MockClass(variables=variables, confirm_variables=False)
      tr._confirm_variables(df_vartypes)
      assert tr.variables_ == variables
  
      tr = MockClass(variables=variables, confirm_variables=True)
      tr._confirm_variables(df_vartypes)
      assert tr.variables_ == variables[2:4]
  
file_path: feature_engine/tests/test_selection/test_base_selector.py
imports: import pytest
  from pandas.testing import assert_frame_equal
  from feature_engine.selection.base_selector import BaseSelector
label_desc: Use image node_id 4 for calling a global function with example usage: test_confirm_variables(df_vartypes) without return types