Unless there's a misunderstanding here, @jspahrsummers asked me to assert that the delegate was of the correct type here, but I had originally just sent a call to the delegate, which also could have failed if the delegate didn't exist. How about something like this?

````objc
return ([self.delegate isKindOfClass:RBLCAAnimationDelegate.class] ? [(RBLCAAnimationDelegate *)self.delegate completion] : nil);
````