protected void renderARIACombobox(FacesContext context, UIInput component) throws IOException {
        ResponseWriter writer = context.getResponseWriter();
        writer.writeAttribute(HTML.ARIA_ROLE, HTML.ARIA_ROLE_COMBOBOX, null);
        writer.writeAttribute(HTML.ARIA_HASPOPUP, HTML.ARIA_ROLE_LISTBOX, null);
        writer.writeAttribute(HTML.ARIA_EXPANDED, "false", null);
    }
Adds ARIA attributes if the component is "role=combobox".

@param context the {@link FacesContext}
@param component the {@link UIInput} component to add attributes for
@throws IOException if any error occurs writing the response
@see <a href="https://www.w3.org/TR/wai-aria-practices/#combobox">Combo Box</a>
primefaces/src/main/java/org/primefaces/renderkit/InputRenderer.java