src/vs/workbench/contrib/notebook/common/model/notebookTextModel.ts/StackOperation/undo
class StackOperation:	async undo(): Promise<void> {
		this._delayedEmitter.beginDeferredEmit();
		for (let i = this._operations.length - 1; i >= 0; i--) {
			await this._operations[i].undo();
		}
		this._postUndoRedo(this._beginAlternativeVersionId);
		this._delayedEmitter.endDeferredEmit(this._beginSelectionState);
	}