Filter query by requestor

I'm trying to put together an IItemQuery that gets all IBuildResults that have been submitted by a certain IContributor, i.e. if they have all been requested by a certain IBuildRequest.getInitiatingContributor().

However, there doesn't appear to be an "IBuildRequestQueryModel", as it were, or any other way of adding this predicate to an IBuildResultQueryModel. Is there any better way than having to check IBuildRequest.getInitiatingControbutor() on all results?

Thanks for your help.