code: private void buildRuntimeTree() {
      updateRuntime();
      Runtime rootInfo = findRuntime();
      root = new RuntimeNode();
      root.setFrameName("_top");
      root.setRuntimeID(rootInfo.getRuntimeID());
  
      List<Runtime> runtimeInfos = Lists.newArrayList(runtimesList.values());
      runtimeInfos.remove(rootInfo);
  
      for (Runtime runtimeInfo : runtimeInfos) {
        addNode(runtimeInfo, root);
      }
    }
docs: Updates the runtimes list to most recent version.