src/vs/workbench/browser/parts/compositeBar.ts/CompositeBarModel/setPinned
class CompositeBarModel:	setPinned(id: string, pinned: boolean): boolean {
		for (const item of this.items) {
			if (item.id === id) {
				if (item.pinned !== pinned) {
					item.pinned = pinned;
					return true;
				}
				return false;
			}
		}
		return false;
	}