code: function(lonLatBounds) {
          var leftBottomPx = this.getOverviewPxFromLonLat({
              lon: lonLatBounds.left,
              lat: lonLatBounds.bottom
          });
          var rightTopPx = this.getOverviewPxFromLonLat({
              lon: lonLatBounds.right,
              lat: lonLatBounds.top
          });
          var bounds = null;
          if (leftBottomPx && rightTopPx) {
              bounds = new OpenLayers.Bounds(leftBottomPx.x, leftBottomPx.y,
                                             rightTopPx.x, rightTopPx.y);
          }
          return bounds;
      }
docs: Method: getRectBoundsFromMapBounds
  Get the rect bounds from the map bounds.
  
  Parameters:
  lonLatBounds - {<OpenLayers.Bounds>}
  
  Returns:
  {<OpenLayers.Bounds>}A bounds which is the passed-in map lon/lat extent
  translated into pixel bounds for the overview map