src/vs/base/parts/ipc/node/ipc.net.ts/WebSocketNodeSocket/drain
class WebSocketNodeSocket:	public async drain(): Promise<void> {
		if (this._zlibDeflateFlushWaitingCount > 0) {
			await Event.toPromise(this._onDidZlibFlush.event);
		}
		await this.socket.drain();
	}