             attributes: nil
         )
         
+        let externalStorageFolderName = ".\(fileURL.deletingPathExtension().lastPathComponent)_SUPPORT"
+        let temporaryExternalStorageURL = temporaryDirectoryURL.appendingPathComponent(
+            externalStorageFolderName,
+            isDirectory: true
+        )
         let temporaryFileURL = temporaryDirectoryURL.appendingPathComponent(
             fileURL.lastPathComponent,
             isDirectory: false

            throw CoreStoreError(error)
        }
        
        let externalStorageDirName = "." + fileURL.deletingPathExtension().lastPathComponent + "_SUPPORT"
        let temporaryExternalStorageURL = temporaryDirectoryURL.appendingPathComponent(
            externalStorageDirName,
            isDirectory: true
        )
        do {
            
            try fileManager.replaceItem(
                at: fileURL as URL,
                withItemAt: temporaryFileURL,
                backupItemName: nil,
                options: [],
                resultingItemURL: nil
            )
            
            if fileManager.fileExists(atPath: temporaryExternalStorageURL.path) {
                let extenralStorageURL = fileURL.deletingLastPathComponent().appendingPathComponent(externalStorageDirName,  isDirectory: true)
                try fileManager.replaceItem(
                    at: extenralStorageURL as URL,
                    withItemAt: temporaryExternalStorageURL,
                    backupItemName: nil,
                    options: [],

                    
                    fakeProgress = 1
                }
                _ = try? storage.cs_finalizeStorageAndWait(soureModelHint: destinationModel)
                progress.completedUnitCount = progress.totalUnitCount
                return
            }
            catch {

                // Lightweight migration failed somehow. Proceed using InferedMappingModel below
            }
        }

