def METHOD_NAME(field_name, override_field):
    original_raw_yaml = {
        'jtype': 'SimpleIndexer',
        'with': {'a': 123, 'b': 'test'},
        'metas': {'name': 'test-name', 'workspace': 'test-work-space'},
        'requests': {'/foo': 'bar'},
    }
    updated_raw_yaml = original_raw_yaml
    JAMLCompatible()._override_yml_params(updated_raw_yaml, field_name, override_field)
    if override_field:
        assert updated_raw_yaml[field_name] == override_field
    else:
        assert original_raw_yaml == updated_raw_yaml
    # assure we don't create py_modules twice
    if override_field == 'metas' and 'py_modules' in override_field:
        assert 'py_modules' in updated_raw_yaml['metas']
        assert 'py_modules' not in updated_raw_yaml