code: function(pxBounds) {
          var leftBottomLonLat = this.getLonLatFromOverviewPx({
              x: pxBounds.left,
              y: pxBounds.bottom
          });
          var rightTopLonLat = this.getLonLatFromOverviewPx({
              x: pxBounds.right,
              y: pxBounds.top
          });
          return new OpenLayers.Bounds(leftBottomLonLat.lon, leftBottomLonLat.lat,
                                       rightTopLonLat.lon, rightTopLonLat.lat);
      }
docs: Method: getMapBoundsFromRectBounds
  Get the map bounds from the rect bounds.
  
  Parameters:
  pxBounds - {<OpenLayers.Bounds>}
  
  Returns:
  {<OpenLayers.Bounds>} Bounds which is the passed-in overview rect bounds
  translated into lon/lat bounds for the overview map