public class Message {
  // save this object
  public Message (Object obj) {
  }
  // save port of the sender of this message. used for return messages.
  public void setSenderPort(Port senderPort) {
  }
  // return the previously saved port
  public Port getSenderPort() {
  }
  // convert the object to a string 
  public String getValue() {
  }
  // store a new object in the message 
  public void setObject(Object obj) {
  }
  // get the object in the message 
  public Object getObject() {
  }
}