processPong(payload) {
		const now = Date.now();
		const elapsedTime = now - payload.time;
		const timeDiff = Math.round(now - payload.arrived - elapsedTime / 2);

		// this.logger.debug(`PING-PONG from '${payload.sender}' - Time: ${elapsedTime}ms, Time difference: ${timeDiff}ms`);

		this.broker.broadcastLocal("$node.pong", {
			nodeID: payload.sender,
			elapsedTime,
			timeDiff,
			id: payload.id
		});

		this.metrics.set(METRIC.MOLECULER_TRANSIT_PONG_TIME, elapsedTime, {
			targetNodeID: payload.sender
		});
		this.metrics.set(METRIC.MOLECULER_TRANSIT_PONG_SYSTIME_DIFF, timeDiff, {
			targetNodeID: payload.sender
		});
	}
Process incoming PONG packet.
Measure ping time & current time difference.

@param {Object} payload
@memberof Transit