Accessibility warning on role="listbox"

[gunzip]

get the following warning from aXe tool:

[Severe] Elements with ARIA roles must ensure required owned elements are present (1)
See AX_ARIA_08 for more information.
<div class=​"owl-carousel owl-theme owl-loaded owl-drag" role=​"listbox" id=​"carousel-1" tabindex=​"0" data-owl-access-keyup=​"1" data-owl-carousel-focusable=​"1">​…​</div>​

[Seika85]

An element with role="listbox" requires its children to have role="option" per definition. The problem is that the child element is the outer-stage and not the owl-items.
I think one would need add role="listbox" to the stage and not to the owl-carousel wrapper.

This could be accomplished by changing the following:

  Owl2A11y.prototype.setupRoot = function() {
//    this.$element.attr({
//      role: 'listbox',
//      tabindex: '0'
//    });

    this._core.$stage.attr({
      role: 'listbox',
      tabindex: '0'
    });
    this._core.$stage.children().each(function() {
      var item = $(this);
      item.attr({
        role: 'option',
      });
    });
  };

But maybe someone with more expertise in the field of accessibility can look over that?