docs: protected void scanSuper(TypeElement e) {
      TypeElement superElement =
          (TypeElement) utils.typeUtils.asElement(e.getSuperclass());
      if (superElement != null) {
        superElement.accept(new ContractExtensionBuilder(), type);
      }
      for (TypeMirror iface : e.getInterfaces()) {
        TypeElement ifaceElement =
            (TypeElement) utils.typeUtils.asElement(iface);
        ifaceElement.accept(new ContractExtensionBuilder(), type);
      }
    }