code: function(features) {
          var name;
          if(OpenLayers.Util.isArray(features)) {
              name = "featureMembers";
          } else {
              name = "featureMember";
          }
          var root = this.writeNode("gml:" + name, features);
          this.setAttributeNS(
              root, this.namespaces["xsi"],
              "xsi:schemaLocation", this.schemaLocation
          );
  
          return OpenLayers.Format.XML.prototype.write.apply(this, [root]);
      }
docs: Method: write
  
  Parameters:
  features - {Array(<OpenLayers.Feature.Vector>) | OpenLayers.Feature.Vector}
  An array of features or a single feature.
  
  Returns:
  {String} Given an array of features, a doc with a gml:featureMembers
  element will be returned.  Given a single feature, a doc with a
  gml:featureMember element will be returned.