docs: 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;
      }