disconnected(nodeID, isUnexpected) {
		let node = this.get(nodeID);
		if (node && node.available) {
			node.disconnected(isUnexpected);

			this.registry.unregisterServicesByNode(node.id);

			this.broker.broadcastLocal("$node.disconnected", { node, unexpected: !!isUnexpected });

			this.registry.updateMetrics();

			if (isUnexpected) this.logger.warn(`Node '${node.id}' disconnected unexpectedly.`);
			else this.logger.info(`Node '${node.id}' disconnected.`);

			if (this.broker.transit) this.broker.transit.removePendingRequestByNodeID(nodeID);
		}
	}
Disconnected a node

@param {String} nodeID
@param {Boolean} isUnexpected
@memberof NodeCatalog