JSON, List Parsing with the R Package Listviewer

I was looking for help with JSON files, and found a package 'Listviewer'; the function jsonedit() creates a tree view of list items (complete with drop-down arrows for moving between a collapsed and expanded view.  The page created with RMarkdown is here (you will have to download a copy to your computer and open it in a browser; Google Drive will show you only the raw html):

First-Attempts-at-JSON-Parsing-Using-Package-Listviewer