@Override
	void handleMessage(ACLMessage msg) {
            switch (msg.getPerformative()) {
            case ACLMessage.QUERY_REF:
                System.out.println("Query Ref received");
                sender = msg.getSender();
                handleExpression(msg.getContent());
            break;
            case ACLMessage.PROPOSE:
                handleProposal(msg);
                break;
            case ACLMessage.INFORM:
                for(Object[] o: expectedReturn){
                    if(o[0].equals(msg.getSender())){
                        handleSolvedExpression(msg);
                    }
                }
                break;
            default:
                    System.out.println("Unsupported Performative" + msg.getPerformative(msg.getPerformative()));
                    break;
            }
	}