How to get DIV id of a canvas inside of a VLayout

[rkumsher]

I am trying to embed 3rd party (JavaScript) visualizations into a VLayout using a Canvas object as the container. The constructor of the visualization requires a div id in order to draw it. This works if I hard code the div id if the Canvas (eg. "isc_3") but how can I get this at run time?

Calling setID()/getID() doesn't seem work. Nor does calling getElement.getId().

Any advice on how to accomplish this?
Thanks