code: def test_check_init_parameter_variables_is_none():
      assert _check_init_parameter_variables(None) is None
  
imports: import pytest
  from feature_engine._variable_handling.init_parameter_checks import _check_init_parameter_variables
label_desc: Use image node_id 3 for calling a global function with example usage: test_check_init_parameter_variables_is_none() without return types