docs: public static String removeFirstWord(String sentence)
    {
      if(sentence == null) {
        return null;
      }
      if(sentence.isEmpty()) {
        return sentence;
      }
  
      String firstWord = firstWord(sentence);
      if(firstWord.length() == sentence.length()) return sentence;
  
      int i = firstWord.length();
      for(; i < sentence.length(); i++) {
        if(WHITE_SPACES.indexOf(sentence.charAt(i)) == -1) break;
      }
      return sentence.substring(i);
    }