         
         //var sampleData = O()
         //sampleData.uid = 0
-        var emptyData = NSMutableData(length: O.dataSize())
+        let emptyData = NSMutableData(length: O.dataSize())
         self.write(emptyData!)
     }
     

    
    func deleteBlock(aID: UID) -> CUnsignedLongLong {
        
        var pos = self.seekToFileID(aID)
        
        var block = Block(used: false)
        
        writeBlock(block)
        

        
        fileHandle.seekToFileOffset(pos)
        
        let block = Block(obj: aObj)
        
        writeBlock(block)
    }
