module foo {
  namespace foons;
  prefix foo;

  identity one;

  list foo {
    key str;
    leaf str {
      type string;
    }
  }

  list bar {
    key qname;
    leaf qname {
      type identityref {
        base one;
      }
    }
  }

  list baz {
    key id;
    leaf id {
      type instance-identifier;
    }
  }
}