src/vs/workbench/api/browser/mainThreadTerminalService.ts/MainThreadTerminalService/$startSendingDataEvents
class MainThreadTerminalService:	public $startSendingDataEvents(): void {
		if (!this._dataEventTracker) {
			this._dataEventTracker = this._instantiationService.createInstance(TerminalDataEventTracker, (id, data) => {
				this._onTerminalData(id, data);
			});
			// Send initial events if they exist
			this._terminalService.instances.forEach(t => {
				t.initialDataEvents?.forEach(d => this._onTerminalData(t.instanceId, d));
			});
		}
	}