      */
     public func jsonValue(key: String) -> UInt?
     {
-        return self[key as! Key] as? UInt
+        return (self[key as! Key] as? NSNumber)?.unsignedIntegerValue
     }
     
     /**

     */
    public func jsonValue(key: String) -> Float?
    {
        return self[key as! Key] as? Float
    }
    
    /**

     */
    public func jsonValue(key: String, defaultValue : Int64 = 0) -> Int64
    {
        return (self[key as! Key] as? NSNumber)?.longLongValue ?? defaultValue
    }
    
    /**
