def versions(configuration):
    """Displays all the versions of a named configuration

    :param ElementTree configuration: the configuration document whose versions should be displayed.
    """
    v = configuration.find('default-version')
    if None == v or None == v.text:
        defaultUrl = None
        defaultNote = ''
    else:
        defaultUrl = v.text
        defaultNote = ' (* indicates the default version)'
    v = configuration.findall('known-versions/known-version')
    print('Currently active version for configuration "' + configuration.
        find('name').text + '"' + defaultNote)
    for vers in v:
        if defaultUrl == vers.find('uri').text:
            header = '* '
        else:
            header = '  '
        if None == vers.find('description') or None == vers.find('description'
            ).text:
            descriptionToUse = ''
        else:
            descriptionToUse = ': ' + vers.find('description').text
        print(header + vers.find('name').text + descriptionToUse)
    print()
