code: public void addChangePlayModeCommand(PlayMode playMode) {
          StringBuilder buf = new StringBuilder();
          buf.append("(change_mode ");
          buf.append(playMode);
          buf.append(')');
          fifo.add(fifo.size(), buf.toString());
      }
docs: Trainer only command.
  Changes the play mode of the server.
  
  @param playMode a {@link com.github.robocup_atan.atan.model.enums.PlayMode} object.