src/vs/workbench/api/browser/mainThreadTask.ts/MainThreadTask/$unregisterTaskProvider
class MainThreadTask:	public $unregisterTaskProvider(handle: number): Promise<void> {
		const provider = this._providers.get(handle);
		if (provider) {
			provider.disposable.dispose();
			this._providers.delete(handle);
		}
		return Promise.resolve(undefined);
	}