src/vs/workbench/browser/parts/compositeBar.ts/CompositeBarModel/addActivity
class CompositeBarModel:	addActivity(id: string, activity: ICompositeActivity): boolean {
		const item = this.findItem(id);
		if (item) {
			const stack = item.activity;
			for (let i = 0; i <= stack.length; i++) {
				if (i === stack.length) {
					stack.push(activity);
					break;
				} else if (stack[i].priority <= activity.priority) {
					stack.splice(i, 0, activity);
					break;
				}
			}
			this.updateActivity(id);
			return true;
		}
		return false;
	}