static box Main {
  main(args) {
    local console = new ConsoleBox()
    local s = "abcde"
    // length
    console.println("len=" + s.length())
    // substring [1,4) -> bcd
    local t = s.substring(1, 4)
    console.println("sub=" + t)
    // lastIndexOf("b") -> 1
    console.println("idx=" + s.lastIndexOf("b"))
    return 0
  }
}