         completion: @escaping (_ finished: Bool) -> Void
         )
     {
-        transition(
-            TransitionParams(
-                mutation: { self.mutation(view) },
-                completion: completion))
+        self.mutation(view)
+        completion(true)
     }
 }

    public
    init(
        id: String = NSUUID().uuidString,
        transition: @escaping (_: TransitionParams) -> Void = { $0.mutation(); $0.completion(true) },
        mutation: @escaping (_ view: TargetView) -> Void
        )
    {
        self.id = id
        self.transition = transition
        self.mutation = mutation
    }
}

//===

public
final
class ViewState<TargetView: UIView>
{
    let id: String
    
    let mutation: (_ view: TargetView) -> Void
    
