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

		const url = collection ? joinPath(this.userDataSyncStoreUrl, 'collection', collection).toString() : joinPath(this.userDataSyncStoreUrl, 'collection').toString();
		headers = { ...headers };

		await this.request(url, { type: 'DELETE', headers }, [], CancellationToken.None);
	}