code: function(newParams) {
          this.params = OpenLayers.Util.extend(this.params, newParams);
          var ret = this.redraw();
          if(this.map != null) {
              this.map.events.triggerEvent("changelayer", {
                  layer: this,
                  property: "params"
              });
          }
          return ret;
      }
docs: APIMethod: mergeNewParams
  
  Parameters:
  newParams - {Object}
  
  Returns:
  redrawn: {Boolean} whether the layer was actually redrawn.