public static ModelNode AddUserCodeWebPart(this ModelNode model, UserCodeWebPartDefinition definition, Action<ModelNode> action)
 {
     return model.AddDefinitionNode(definition, action);
 }
 public static ModelNode AddUserCodeWebPart(this ModelNode model, UserCodeWebPartDefinition definition)
 {
     return AddUserCodeWebPart(model, definition, null);
 }