Translate c script in java

Hi there,
I have trouble in translating c# in js. Here is the c# version:

correctHeadRot = (Vector3)stream.ReceiveNext();

Can you help me how can I write that ,Vector3, in js?
-Thanks

correctHeadRot = stream.ReceiveNext() as Vector3;

Here is an explanation:
How to perform Explicit typecasting in UnityScript? - Unity Answers