docs: function() {
      var e = this._element;
      if (!e) return null;
      if (typeof e.getBoundingClientRect !== 'function') {
        console.error("[wdg.rect] This element has non `getBoundingClientRect` function:", e);
      }
      var r = e.getBoundingClientRect();
      if( typeof r.width === 'undefined' ) r.width = r.right - r.left;
      if( typeof r.height === 'undefined' ) r.height = r.bottom - r.top;
      return r;
    }