@Test
public void getOrAdd_NestedMap() throws Exception {

  Schema expectedSchema = Schema.builder()
      .setName("Map_String_Map_String_String")
      .setType("object")
      .setMapValueSchema(Field.builder()
          .setName(SchemaRepository.MAP_UNUSED_MSG)
          .setType(FieldType.OBJECT)
          .setSchemaReference(SchemaReference.create(repo, config,
              new TypeToken<Map<String, String>>() {}))
          .build())
      .build();
  assertThat(repo.getOrAdd(getMethodConfig("getNestedMap").getReturnType(), config))
      .isEqualTo(expectedSchema);
}