static box Main {
  main(args) {
    local json = "{\"a\":{\"n\":7,\"s\":\"B\"},\"arr\":[1,2,3]}"
    local doc = new JsonDocBox()
    doc.parse(json)
    local root = doc.root()
    // prints: B, 7, 3, 2
    print(root.get("a").get("s").str())
    print(root.get("a").get("n").int())
    local arr = root.get("arr")
    print(arr.size())
    print(arr.at(1).int())
    return 0
  }
}