in src/main/resources/SLING-INF/libs/sling/resource-editor/static/js/tree/TreeController.js [306:311]
TreeController.prototype.openAddNodeDialog = function(li) {
var thatTreeController = this;
var resourcePath = this.getPathFromLi(li);
var nodeTypeName = li.attr("nodetype");
this.addNodeController.openAddNodeDialog(resourcePath, nodeTypeName);
}