That's what it looks like. But check this out: 


    canVoid: function (callback) {
      callback(this.get('isPosted') || XT.session.privileges.get("VoidPostedCashReceipts"));
    }

Here, the privilege itself is a necessary clause of the predicate, and is not a strict precondition. Should I leave this one as-is, or is there a pattern for this as well?