Polling a Build Engine for specific buildDefId requests

Hi,

I'm trying to poll a build engine for pending requests. I can get the next request from the queue, and look at the buildDefinitionId which it is associated with. If the request is for a buildDefinitionId I'm not interested in, how can I set the status of the request back so that the next time the requests queue is polled this request is seen? I've found isProcessed() and setProcessed(boolean) but the latter throws null pointers when I call it.

Is there something I'm missing?

Hope someone can help.

TIA

Cheers, Andrew