src/vs/workbench/browser/parts/compositeBar.ts/CompositeBarModel/findIndex
class CompositeBarModel:	private findIndex(id: string): number {
		for (let index = 0; index < this.items.length; index++) {
			if (this.items[index].id === id) {
				return index;
			}
		}
		return -1;
	}