[System.Security.SecurityCritical] // auto-generated
        #endif
        private static string FetchOrCreateStore(string groupName, string storeName, IsolatedStorageFile isf) {
            string groupRootPath = GetGroupPathFromName(groupName);
            string obfuscatedStoreName = GetHash(storeName);
            string obfuscatedGroupName = GetHash(groupName);
            string storeRootPath = Path.Combine(IsolatedStorageRoot, Path.Combine(s_StorePathPrefix, obfuscatedStoreName));

            FileLock rootLock = FileLock.GetFileLock(IsolatedStorageRoot);

            try {
                rootLock.Lock();

                if(Directory.UnsafeExists(storeRootPath)) {

                    if (!File.UnsafeExists(Path.Combine(storeRootPath, s_IdFileName))) {
                        File.UnsafeWriteAllText(Path.Combine(storeRootPath, s_IdFileName), storeName);
                    } else {
                        if (!storeName.Equals(File.UnsafeReadAllText(Path.Combine(storeRootPath, s_IdFileName)))) {
                            throw new IsolatedStorageException(Environment.GetResourceString("IsolatedStorage_Init"));
                        }
                    }

                    File.UnsafeWriteAllText(Path.Combine(storeRootPath, s_GroupFileName), obfuscatedGroupName);
                    

                    if (!Directory.UnsafeExists(Path.Combine(storeRootPath, s_FilesPathPrefix))) {
                        Directory.UnsafeCreateDirectory(Path.Combine(storeRootPath, s_FilesPathPrefix));
                    }

                    if(File.UnsafeExists(Path.Combine(storeRootPath, s_CleanupFileName))) {
                        bool removedAll = isf.CleanDirectory(Path.Combine(storeRootPath, s_FilesPathPrefix));

                        if(removedAll) {
                            File.UnsafeDelete(Path.Combine(storeRootPath, s_CleanupFileName));
                            return storeRootPath;
                        } else {
                            throw new IsolatedStorageException(Environment.GetResourceString("IsolatedStorage_Init"));
                        }
                    } else {
                        return storeRootPath;
                    }
                } else {
                    isf.Reserve(s_DirSize);
                    Directory.UnsafeCreateDirectory(storeRootPath);
                    TouchFile(Path.Combine(storeRootPath, s_CleanupFileName));

                    Directory.UnsafeCreateDirectory(Path.Combine(storeRootPath, s_FilesPathPrefix));
                    File.UnsafeWriteAllText(Path.Combine(storeRootPath, s_GroupFileName), obfuscatedGroupName);
                    File.UnsafeWriteAllText(Path.Combine(storeRootPath, s_IdFileName), storeName);
                    File.UnsafeDelete(Path.Combine(storeRootPath, s_CleanupFileName));
                    return storeRootPath;
                }
            } catch(IOException e) {
                throw GetIsolatedStorageException("IsolatedStorage_Init", e);
            } catch (UnauthorizedAccessException e) {
                throw GetIsolatedStorageException("IsolatedStorage_Init", e);
            } finally {
                if(rootLock != null) {
                    rootLock.Unlock();
                }
            }
        }