     }
 }
 
-public protocol ContentMappable {
+public protocol ContentInitializable {
     init(content: Content) throws
+}
+
+public protocol ContentMappable: ContentInitializable {
     static var key: String { get }
 }
 

            upgrade: upgrade
        )

        self.content = convertible.content
    }
}


            upgrade: upgrade
        )

        self.content = content.content
    }
}