code: public static List<String> split(String input, String punctuationChars, String quoteChars) {
  		return split(input, punctuationChars, quoteChars, false, false, false);
  	}
docs: reads all words in a text and converts them to lower case
  
  @param input
  @param punctuationChars characters that can not belong to words and are therefore separators
  @return a collection of uniquely identified words