     
     struct Test : Init {
         
-        var a : Int
+        var a : Int  // 8 bytes
         
         init() {
             a = 0;

        
        result = dataStore.readBlock(uid);
        
        XCTAssertEqual(result.a,44,"")
    }
    
}

/**

        
        XCTAssertFalse(url.isFileExisting(), "File not deleted?");
    }
    */
    
    func test1StoreFile() {
        var url = testFile()
        
        NSLog("URL: %@", url.path!)
        url.deleteFile()
        
        var dataStore = DataStore<TestHeader,Test>(url: url)
        
        XCTAssertTrue(url.isFileExisting(),"A file exist?");
        
        //XCTAssertNotNil(dataStore.fileHandle,"file is not created")
        XCTAssertNil(dataStore.error, "error happend?");
        
        //var dataValue = Test(num:42)
        //var uid = dataStore.createBlock(dataValue)
        
        url.deleteFile()
        
        XCTAssertFalse(url.isFileExisting(),"File not deleted?");
    }

    //
    //  Create new DataStore
    //  write a block
    //  reopen this DataStore
    //  read the block
    func test3WriteData() {
        
        var url = testFile()
