 {
     let id: String
     
-    let body: (UFLModel, (() -> Action<UFLModel>) -> Void) throws -> Mutations<UFLModel>
+    let body: (UFLModel, @escaping (() -> Action<UFLModel>) -> Void) throws -> Mutations<UFLModel>
 }
 
 //===

    static
    func trigger<UFLModel>(
        _ name: String = #function,
        _ body: @escaping (UFLModel, (() -> Action<UFLModel>) -> Void) throws -> Void
        ) -> Action<UFLModel>
    {
        return Action(id: "\(self).\(name)", body: { try body($0, $1); return { _ in } })

    static
    func action<UFLModel>(
        _ name: String = #function,
        _ body: @escaping (UFLModel, @escaping (() -> Action<UFLModel>) -> Void) throws -> Mutations<UFLModel>
        ) -> Action<UFLModel>
    {
        return Action(id: "\(self).\(name)", body: body)
