src/vs/base/parts/ipc/common/ipc.ts/ChannelServer/onEventListen
class ChannelServer:	private onEventListen(request: IRawEventListenRequest): void {
		const channel = this.channels.get(request.channelName);

		if (!channel) {
			this.collectPendingRequest(request);
			return;
		}

		const id = request.id;
		const event = channel.listen(this.ctx, request.name, request.arg);
		const disposable = event(data => this.sendResponse(<IRawResponse>{ id, data, type: ResponseType.EventFire }));

		this.activeRequests.set(request.id, disposable);
	}