 ///
 /// Must be a top-level type because Deferred is generic.
 
-public enum DeferredError: Error
+public enum DeferredError: Error, Equatable
 {
   case canceled(String)
   case invalid(String)

  default:                                     return false
  }
}

  }
}

#if !swift(>=4.1)
public func == (a: DeferredError, b: DeferredError) -> Bool
{
  switch (a,b)
