src/vs/workbench/api/common/extHostTypes.ts/TaskGroup/constructor
class TaskGroup:	constructor(id: string, _label: string) {
		if (typeof id !== 'string') {
			throw illegalArgument('name');
		}
		if (typeof _label !== 'string') {
			throw illegalArgument('name');
		}
		this._id = id;
	}