docs: private void write(PrintWriter writer, Janitor janitor, List messages, String txt) {
          if (messages==null || messages.isEmpty()) return;
          Iterator iterator = messages.iterator();
          while (iterator.hasNext()) {
              Message message = (Message) iterator.next();
              message.write(writer, janitor);
              
              if (configuration.getDebug() && (message instanceof SyntaxErrorMessage)){
                  SyntaxErrorMessage sem = (SyntaxErrorMessage) message;
                  sem.getCause().printStackTrace(writer);
              } 
              writer.println();
          }
  
          writer.print(messages.size());
          writer.print(" "+txt);
          if (messages.size()>1) writer.print("s");
          writer.println();
      }