docs: function(bounds, worldBounds) {
          this.featureDx = 0;
          if (worldBounds) {
              var worldWidth = worldBounds.getWidth(),
                  rendererCenterX = (this.extent.left + this.extent.right) / 2,
                  featureCenterX = (bounds.left + bounds.right) / 2,
                  worldsAway = Math.round((featureCenterX - rendererCenterX) / worldWidth);
              this.featureDx = worldsAway * worldWidth;
          }
      }