import Lean.Server.Rpc.Basic open Lean Server structure FooRef where a : Array Nat deriving RpcEncoding with { withRef := true } structure FooJson where s : String deriving FromJson, ToJson structure Bar where fooRef : WithRpcRef FooRef fooJson : FooJson deriving RpcEncoding structure BarTrans where bar : Bar deriving RpcEncoding structure Baz where arr : Array String -- non-constant field deriving RpcEncoding