src/vs/workbench/contrib/notebook/common/notebookOptions.ts/NotebookOptions/_computeShowFoldingControlsOption
class NotebookOptions:	private _computeShowFoldingControlsOption() {
		return this.configurationService.getValue<'always' | 'never' | 'mouseover'>(NotebookSetting.showFoldingControls) ?? 'mouseover';
	}