src/vs/platform/userDataSync/common/extensionsStorageSync.ts/ExtensionsStorageSyncService/initialize
class ExtensionsStorageSyncService:	private initialize(): void {
		const keys = this.storageService.keys(StorageScope.GLOBAL, StorageTarget.MACHINE);
		for (const key of keys) {
			const extensionIdWithVersion = ExtensionsStorageSyncService.fromKey(key);
			if (extensionIdWithVersion) {
				this.extensionsWithKeysForSync.add(extensionIdWithVersion.id.toLowerCase());
			}
		}
	}