src/vs/workbench/api/browser/mainThreadComments.ts/MainThreadComments/$unregisterCommentController
class MainThreadComments:	$unregisterCommentController(handle: number): void {
		const providerId = this._handlers.get(handle);
		this._handlers.delete(handle);
		this._commentControllers.delete(handle);

		if (typeof providerId !== 'string') {
			return;
			// throw new Error('unknown handler');
		} else {
			this._commentService.unregisterCommentController(providerId);
		}
	}