src/vs/workbench/api/browser/mainThreadSCM.ts/MainThreadSCM/$registerGroups
class MainThreadSCM:	$registerGroups(sourceControlHandle: number, groups: [number /*handle*/, string /*id*/, string /*label*/, SCMGroupFeatures][], splices: SCMRawResourceSplices[]): void {
		const repository = this._repositories.get(sourceControlHandle);

		if (!repository) {
			return;
		}

		const provider = repository.provider as MainThreadSCMProvider;
		provider.$registerGroups(groups);
		provider.$spliceGroupResourceStates(splices);
	}