docs: function(id, geometry, style, featureId) {
          var backgroundStyle = OpenLayers.Util.extend({}, style);
          
          // Set regular style attributes to apply to the background styles.
          backgroundStyle.externalGraphic = backgroundStyle.backgroundGraphic;
          backgroundStyle.graphicXOffset = backgroundStyle.backgroundXOffset;
          backgroundStyle.graphicYOffset = backgroundStyle.backgroundYOffset;
          backgroundStyle.graphicZIndex = backgroundStyle.backgroundGraphicZIndex;
          backgroundStyle.graphicWidth = backgroundStyle.backgroundWidth || backgroundStyle.graphicWidth;
          backgroundStyle.graphicHeight = backgroundStyle.backgroundHeight || backgroundStyle.graphicHeight;
          
          // Erase background styles.
          backgroundStyle.backgroundGraphic = null;
          backgroundStyle.backgroundXOffset = null;
          backgroundStyle.backgroundYOffset = null;
          backgroundStyle.backgroundGraphicZIndex = null;
          
          return this.redrawNode(
              id + this.BACKGROUND_ID_SUFFIX, 
              geometry, 
              backgroundStyle, 
              null
          );
      }