src/vs/workbench/browser/parts/views/viewsService.ts/ViewsService/openComposite
class ViewsService:	private async openComposite(compositeId: string, location: ViewContainerLocation, focus?: boolean): Promise<IPaneComposite | undefined> {
		if (location === ViewContainerLocation.Sidebar) {
			return this.viewletService.openViewlet(compositeId, focus);
		} else if (location === ViewContainerLocation.Panel) {
			return this.panelService.openPanel(compositeId, focus) as Promise<IPaneComposite>;
		}
		return undefined;
	}