docs: private static void checkPreconditions(final List<String> forbiddenSubStrings) {
  		if( forbiddenSubStrings == null ) {
  			throw new NullPointerException("forbiddenSubStrings list should not be null");
  		} else if( forbiddenSubStrings.isEmpty() ) {
  			throw new IllegalArgumentException("forbiddenSubStrings list should not be empty");
  		}
  	}