support for interface implementing interfaces

[Xample]

According to this spec: https://github.com/graphql/graphql-spec/pull/373 it is possible for interface to implement other interface. However, when I try to do so, no schema seems to be generated. {"errors":[{"message":"GraphQL middleware options must contain a schema."}]} Is this not supported yet, or I'm doing it wrong ?

This fails

interface A {
  id: ID!
}

interface B implements A {
    id:ID!
    value: String
}

type Test implements A & B {
   id: ID!
   value: String
   data: String
}

While this works

interface A {
  id: ID!
}

interface B {
    id:ID!
    value: String
}

type Test implements A & B {
   id: ID!
   value: String
   data: String
}