code: private void notifyListeners() {
          WriterListener[] writerListeners;
          synchronized (listeners) {
              writerListeners = new WriterListener[listeners.size()];
              listeners.toArray(writerListeners);
          }
          String str = stringBuilder.toString();
          stringBuilder.setLength(0);
          for (WriterListener writerListener : writerListeners) {
              writerListener.write(str);
          }
      }
docs: Notify that a new string has been written.