src/vs/platform/userDataSync/common/userDataSyncStoreService.ts/UserDataSyncStoreClient/getAllCollections
class UserDataSyncStoreClient:	async getAllCollections(headers: IHeaders = {}): Promise<string[]> {
		if (!this.userDataSyncStoreUrl) {
			throw new Error('No settings sync store url configured.');
		}

		const url = joinPath(this.userDataSyncStoreUrl, 'collection').toString();
		headers = { ...headers };
		headers['Content-Type'] = 'application/json';

		const context = await this.request(url, { type: 'GET', headers }, [], CancellationToken.None);

		return (await asJson<string[]>(context)) || [];
	}