code: public static boolean isAuthority(String authString) {
  		Matcher m = AUTHORITY_REGEX.matcher(authString);
  		
  		return (m != null) && m.matches();
  	}
docs: Tests if the String argument looks like it could be a legitimate
  authority fragment of a URL, that is, is it an IP address, or, are the
  characters legal in an authority, and does the string end with a legal
  TLD.
  
  @param authString String representation of a fragment of a URL
  @return boolean indicating whether urlPart might be an Authority.