src/vs/workbench/browser/parts/sidebar/sidebarActions.ts/FocusSideBarAction/run
class FocusSideBarAction:	async run(accessor: ServicesAccessor): Promise<void> {
		const layoutService = accessor.get(IWorkbenchLayoutService);
		const paneCompositeService = accessor.get(IPaneCompositePartService);

		// Show side bar
		if (!layoutService.isVisible(Parts.SIDEBAR_PART)) {
			layoutService.setPartHidden(false, Parts.SIDEBAR_PART);
			return;
		}

		// Focus into active viewlet
		const viewlet = paneCompositeService.getActivePaneComposite(ViewContainerLocation.Sidebar);
		viewlet?.focus();
	}