src/vs/workbench/contrib/terminal/browser/terminalInstance.ts/TerminalInstance/_onProcessData
class TerminalInstance:	private _onProcessData(ev: IProcessDataEvent): void {
		const messageId = ++this._latestXtermWriteData;
		if (ev.trackCommit) {
			ev.writePromise = new Promise<void>(r => {
				this.xterm?.raw.write(ev.data, () => {
					this._latestXtermParseData = messageId;
					this._processManager.acknowledgeDataEvent(ev.data.length);
					r();
				});
			});
		} else {
			this.xterm?.raw.write(ev.data, () => {
				this._latestXtermParseData = messageId;
				this._processManager.acknowledgeDataEvent(ev.data.length);
			});
		}
	}