sendPong(payload) {
		return this.publish(
			new Packet(P.PACKET_PONG, payload.sender, {
				time: payload.time,
				id: payload.id,
				arrived: Date.now()
			})
		).catch(
			/* istanbul ignore next */ err => {
				this.logger.error(`Unable to send PONG packet to '${payload.sender}' node.`, err);

				this.broker.broadcastLocal("$transit.error", {
					error: err,
					module: "transit",
					type: C.FAILED_SEND_PONG_PACKET
				});
			}
		);
	}
Send back pong response

@param {Object} payload
@returns
@memberof Transit