static box Main {
  main(args) {
    local console = new ConsoleBox()
    local m = new MapBox()
    m.set("a", 1)
    m.set("b", 2)
    console.println("msz=" + m.size())
    console.println("ha=" + m.has("a"))
    console.println("hc=" + m.has("c"))
    console.println("ga=" + m.get("a"))
    return 0
  }
}