code: public String push(String msg, long delay) throws IOException {
          Message message = new Message();
          message.setBody(msg);
          message.setDelay(delay);
  
          Messages msgs = new Messages(message);
  
          IronReader reader = client.post("queues/" + name + "/messages", msgs);
          Ids ids = gson.fromJson(reader.reader, Ids.class);
          reader.close();
          return ids.getId(0);
      }
docs: Pushes a message onto the queue.
  
  @param msg The body of the message to push.
  @param delay The message's delay in seconds.
  @return The new message's ID
  
  @throws io.iron.ironmq.HTTPException If the IronMQ service returns a status other than 200 OK.
  @throws java.io.IOException If there is an error accessing the IronMQ server.