code: def normalize_os_name(os_name):
    
    if os_name not in OS_ALIASES:
      for proper_name, aliases in OS_ALIASES.items():
        if os_name in aliases:
          return proper_name
      logger.warning('Unknown operating system name: {bad}, known names are: {known}'
                     .format(bad=os_name, known=', '.join(sorted(known_os_names()))))
    return os_name
docs: :API: public