#import @interface SSignal (SideEffects) - (SSignal *)onStart:(void (^)())f; - (SSignal *)onNext:(void (^)(id next))f; - (SSignal *)afterNext:(void (^)(id next))f; - (SSignal *)onError:(void (^)(id error))f; - (SSignal *)onCompletion:(void (^)())f; - (SSignal *)afterCompletion:(void (^)())f; - (SSignal *)onDispose:(void (^)())f; @end