code: public static VersionNumber parseOperatingSystemVersion(@Nonnull final OperatingSystemFamily family, @Nonnull final String userAgent) {
  		Check.notNull(family, "family");
  		Check.notNull(userAgent, "userAgent");
  		return VersionParser.parseOperatingSystemVersion(family, userAgent);
  	}
docs: Try to determine the version number of the operating system by parsing the user agent string.
  
  
  @param family
  family of the operating system
  @param userAgent
  user agent string
  @return extracted version number