     
 }
 
-class ObjectBlock : NSObject, NSCoding {
+// Accoriding related unit test the size of this class is 81 Bytes
+internal class Block : NSObject, NSCoding {
     
     var used: Bool = true
-    var obj: SOCoding? = nil
+    var obj: AnyObject? = nil
     
     override init() {
         super.init()

    }
    
    // subclasses could override this to further analyse header
    func analyseUsedBlock(block: ObjectBlock, forUID uid:UID) {
        
    }
    

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