[Yep,](https://github.com/ReactiveCocoa/ReactiveCocoa/blob/c01fe91544bd6d92580173ebf805441a0b8230cd/ReactiveCocoaFramework/ReactiveCocoa/RACEvent.m#L35) [It's](https://github.com/ReactiveCocoa/ReactiveCocoa/blob/c01fe91544bd6d92580173ebf805441a0b8230cd/ReactiveCocoaFramework/ReactiveCocoa/RACSignal%2BOperations.m#L778) [fine](https://github.com/ReactiveCocoa/ReactiveCocoa/blob/c01fe91544bd6d92580173ebf805441a0b8230cd/ReactiveCocoaFramework/ReactiveCocoa/RACSerialDisposable.m#L38).