docs: function (out) {
              // --------------------------------------------------- destructuring
  
              var cfg = this._cfg;
  
              var waiAria = cfg.waiAria;
              var waiTitleTag = cfg.waiTitleTag;
  
              // ------------------------------------------------------ processing
  
              this._frame.writeMarkupBegin(out);
  
              if (waiAria) {
                  var waiElementId = this._createDynamicId();
                  this._waiElementId = waiElementId;
  
                  if (waiTitleTag) {
                      out.write('<' + waiTitleTag + '>');
                  }
                  out.write('<a id="' + waiElementId + '" ' + this._getWaiAriaAttributesMarkup() + '>');
              }
          }