src/vs/workbench/browser/parts/activitybar/activitybarPart.ts/ActivitybarPart/storeCachedViewContainersState
class ActivitybarPart:	private storeCachedViewContainersState(cachedViewContainers: ICachedViewContainer[]): void {
		this.setPinnedViewContainers(cachedViewContainers.map(({ id, pinned, visible, order }) => (<IPinnedViewContainer>{
			id,
			pinned,
			visible,
			order
		})));

		this.setPlaceholderViewContainers(cachedViewContainers.map(({ id, icon, name, views, isBuiltin }) => (<IPlaceholderViewContainer>{
			id,
			iconUrl: URI.isUri(icon) ? icon : undefined,
			themeIcon: ThemeIcon.isThemeIcon(icon) ? icon : undefined,
			name,
			isBuiltin,
			views
		})));
	}