OpenLayers.Layer.Data = OpenLayers.Class(OpenLayers.Layer, {
setVisibility: function(vis) {
OpenLayers.Layer.Data = OpenLayers.Class(OpenLayers.Layer, {
setVisibility: function(vis) {
OpenLayers.Layer.prototype.setVisibility.apply(this, arguments);
if (!this.map) { return; }
OpenLayers.Layer.prototype.setVisibility.apply(this, arguments);
if (!this.map) { return; }