private String validateParentApiPath(Class<?> cls) {
    Path apiPath = AnnotationUtils.findAnnotation(cls, Path.class);
    if (null == apiPath) {
      logger.warn("Parent api {} also seems to be a nested API. The current version does not support " +
              "multi-level nesting.", cls.getSimpleName());
      return "";
    }
    else {
      return apiPath.value();
    }
  }
Original method is overwritten so that to gather information about top level api - nested api relations
ambari-utility/src/main/java/org/apache/ambari/swagger/AmbariSwaggerReader.java