src/vs/workbench/api/browser/mainThreadSCM.ts/MainThreadSCMProvider/$unregisterGroup
class MainThreadSCMProvider:	$unregisterGroup(handle: number): void {
		const group = this._groupsByHandle[handle];

		if (!group) {
			return;
		}

		delete this._groupsByHandle[handle];
		this.groups.splice(this.groups.elements.indexOf(group), 1);
		this._onDidChangeResources.fire();
	}