How to prevent duplicate id?

Hi guys,

i'm using ext js 3.4.

I had a problem because I had two objects with the same ID. Now i solved the problem creating a unique id for each element.

Anyway, is there something that can check, when i create a new obj, if the id is already present in Ext?

I noticed that in the 4.1 there is it in dev mode. And in 3.4?

How to prevent duplicate id?