src/vs/workbench/contrib/notebook/browser/viewModel/notebookViewModel.ts/NotebookViewModel/changeModelDecorations
class NotebookViewModel:	changeModelDecorations<T>(callback: (changeAccessor: IModelDecorationsChangeAccessor) => T): T | null {
		const changeAccessor: IModelDecorationsChangeAccessor = {
			deltaDecorations: (oldDecorations: ICellModelDecorations[], newDecorations: ICellModelDeltaDecorations[]): ICellModelDecorations[] => {
				return this._deltaModelDecorationsImpl(oldDecorations, newDecorations);
			}
		};

		let result: T | null = null;
		try {
			result = callback(changeAccessor);
		} catch (e) {
			onUnexpectedError(e);
		}

		changeAccessor.deltaDecorations = invalidFunc;

		return result;
	}