src/vs/workbench/api/node/extHostTunnelService.ts/ExtHostTunnelService/$closeTunnel
class ExtHostTunnelService:	async $closeTunnel(remote: { host: string, port: number }, silent?: boolean): Promise<void> {
		if (this._extensionTunnels.has(remote.host)) {
			const hostMap = this._extensionTunnels.get(remote.host)!;
			if (hostMap.has(remote.port)) {
				if (silent) {
					hostMap.get(remote.port)!.disposeListener.dispose();
				}
				await hostMap.get(remote.port)!.tunnel.dispose();
				hostMap.delete(remote.port);
			}
		}
	}