#import #pragma clang assume_nonnull begin @interface Clazz : NSObject -(void)doSomethingMultiResultFlaggyWithCompletionHandler:(void (^)(BOOL, NSString *_Nullable, NSError *_Nullable, NSString *_Nullable))completionHandler __attribute__((swift_async_error(zero_argument, 1))); @end #pragma clang assume_nonnull end