def normalize_os_name(os_name):
  """
  :API: public
  """
  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
:API: public