src/vs/workbench/contrib/notebook/browser/contrib/fold/folding.ts/FoldingController/_updateEditorFoldingRanges
class FoldingController:	private _updateEditorFoldingRanges() {
		if (!this._foldingModel) {
			return;
		}

		this._notebookEditor.viewModel!.updateFoldingRanges(this._foldingModel.regions);
		const hiddenRanges = this._notebookEditor.viewModel!.getHiddenRanges();
		this._notebookEditor.setHiddenAreas(hiddenRanges);
	}