builder

builder
Type: nsIXULTemplateBuilder
For content generated from a template, this is the XPCOM object that is responsible for generating the content. For scripts it is only necessary in case you want to force the template content to be regenerated. You may need to do this if you have adjusted the rules manually. To rebuild the content call the builder's rebuild method.
For example, given a reference to a tree myTree, this example will rebuild its content: myTree.builder.rebuild();