code: public static boolean hasSubPrefix(List<String> tokens) {
  	return tokens.stream().anyMatch( token -> token.toLowerCase().startsWith( "sub" ));        
      }
docs: A case insensitive test of whether any of the supplied tokens
  begins with 'sub'.
  @param tokens a list of strings to test
  @return {@code true} if any token begins with 'sub' regardless of case