Templating the constraint as of 2018.07.12, results in error I hope you have a better title or know were to file this one, or whether it should be a feature request. // Error, Key A only refers to a type but is being used here as a value. ```.ts function KeyRef<O extends {}, KeyA extends keyof O, keyB extends O[KeyA]>(object : O, KeyA : KeyA, KeyB : KeyB) : string [] function KeyRef<O extends {}, KeyA extends keyof O>(object : O, K : KeyA) : string [] function KeyRef<O extends {}, S extends any>(object : O, Keys : any) : string [] ```