         
         // store SampleData as ID:0 in the file
         // ID:0 is a reserved ID and should not be availabled for public access
-        let block = ObjectBlock(used: false)
+        let block = Block(used: false)
         self.writeBlock(block)
         
         //var sampleData = O()

        super.init()
        
        used  = decoder.decodeBoolForKey("1")
        obj = (decoder.decodeObjectForKey("0") as! SOCoding)
    }
    
    @objc func encodeWithCoder(encoder: NSCoder) {

        self.seekToFileID(index)
        
        let data = readBlock()
        let block = FastCoder.objectWithData(data) as! Block
        
        return block.obj as! O
    }
