How to use the setoptconf.String function in setoptconf

def build_manager():
    manager = soc.ConfigurationManager('prospector')

    manager.add(soc.BooleanSetting('zero_exit', default=False))

    manager.add(soc.BooleanSetting('autodetect', default=True))
    manager.add(soc.ListSetting('uses', soc.String, default=[]))

    manager.add(soc.BooleanSetting('blending', default=True))

    manager.add(soc.BooleanSetting('doc_warnings', default=None))
    manager.add(soc.BooleanSetting('test_warnings', default=None))
    manager.add(soc.BooleanSetting('no_style_warnings', default=None))
    manager.add(soc.BooleanSetting('member_warnings', default=None))
    manager.add(soc.BooleanSetting('full_pep8', default=None))
    manager.add(soc.IntegerSetting('max_line_length', default=None))

    manager.add(soc.BooleanSetting('messages_only', default=False))
    manager.add(soc.BooleanSetting('summary_only', default=False))
    manager.add(soc.ListSetting(
        'output_format',
        OutputChoice(sorted(FORMATTERS.keys())),
        default=None,

manager.add(soc.ListSetting('profiles', soc.String, default=[]))
    manager.add(soc.ListSetting('profile_path', soc.String, default=[]))
    manager.add(soc.ChoiceSetting(
        'strictness',
        ['veryhigh', 'high', 'medium', 'low', 'verylow'],
        default=None,
    ))
    manager.add(soc.BooleanSetting('show_profile', default=False))

    manager.add(soc.BooleanSetting('no_external_config', default=False))
    manager.add(soc.StringSetting('pylint_config_file', default=None))

    manager.add(soc.StringSetting('path', default=None))

    manager.add(soc.ListSetting('ignore_patterns', soc.String, default=[]))
    manager.add(soc.ListSetting('ignore_paths', soc.String, default=[]))

    manager.add(soc.BooleanSetting('die_on_tool_error', default=False))
    manager.add(soc.BooleanSetting('include_tool_stdout', default=False))
    manager.add(soc.BooleanSetting('direct_tool_stdout', default=False))

    return manager