             }
         }
     }
-    
+
     public var uInt64Value: UInt64 {
         get {
             return self.numberValue.unsignedLongLongValue


//MARK: - Null
extension JSON {
    
    public var null: NSNull? {
        get {
            switch self.type {

            }
        }
    }

    /// If `type` is `.Dictionary`, return json which's object is `dictionary[key]` , otherwise return null json with error.
    private subscript(key key: String) -> JSON {
        get {
