import re


def get_clean_version_string(version):
    """
    Returns version string used for current app launch stripped of
    any ()'s defining additional version tokens. For example, if
    the version setting is "(8.4)v6" this will return "8.4v6"

    :param version: version of the application being launched
                    specified by the value from 'versions' settings.
                    If no 'versions' were defined in the settings,
                    then this will be None.

    :returns: Version string used to launch application.
    """
    return re.sub("[()]", "", version) if version else None