public String toCommandString(String payload) {
		StringBuffer sb = new StringBuffer();
		sb.append(this.method);
		sb.append('|');
		sb.append(this.subject);
		sb.append('|');
		sb.append(this.widgetId == null ? "null" : this.widgetId);
		sb.append('|');
		sb.append((payload == null || payload.trim().equals("")) ? "null" : payload);
		sb.append('|');
		sb.append(this.callId);
		sb.append("|END");

		return sb.toString();
	}