Is there a way to specify a response as a map, with unknown keys, rather than a struct with the known ones? For instance:

  operation :data1,
    summary: "Balance info and some other info",
    parameters: [
      ......
    ],
    responses: [
      ok: {"Balance info and some other info", "application/json", MyAppSchemas.BalanceInfoEx}
  ]

===>

  operation :data1,
    summary: "Balance info and some other info",
    parameters: [
      ......
    ],
    responses: [
      # something like
      # 1
      # ok: {"Balance info and some other info", "application/json", %{}}
      # OR
      # 2
      ok: {"Balance info and some other info", "application/json", Map}
  ]