anchor.diff:  
   [source,scala]
   ----
  -@Command(name = "MyApp", version = Array("Scala picocli demo v3.0"),
  -  mixinStandardHelpOptions = true, // add --help and --version options
  -  description = Array("@|bold Scala|@ @|underline picocli|@ example"))
  +@Command(name = "MyApp", version = Array("Scala picocli v3.0 demo"),
  +    mixinStandardHelpOptions = true, // add --help and --version options
  +    description = Array("@|bold Scala|@ @|underline picocli|@ example"))
   class MyApp extends Runnable {
   
  -  @Option(names = Array("-c", "--count"), paramLabel = "COUNT",
  -    description = Array("number of repetitions"))
  -  private var count: Int = 1
  -
  -  def run() : Unit = {
  -    for (i <- 0 until count) {
  -      println(s"hello world $i...")
  +    @Option(names = Array("-c", "--count"),
  +            description = Array("number of repetitions"))
  +    private var count: Int = 1
  +
  +    def run() : Unit = {
  +        for (i <- 0 until count) {
  +            println(s"hello world $i...")
  +        }
       }
  -  }
   }
   object MyApp {
  -  def main(args: Array[String]) {
  -    CommandLine.run(new MyApp(), args: _*)
  -  }
  +    def main(args: Array[String]) {
  +        CommandLine.run(new MyApp(), args: _*)
  +    }
   }
   ----
   
  
positive.code: 
  [source,groovy]
  ----
  @Command(name = "MyApp", version = "Groovy picocli demo v3.0",
           mixinStandardHelpOptions = true, // add --help and --version options
           description = "@|bold Groovy|@ @|underline picocli|@ example")
  class MyApp implements Runnable {
  
      @Option(names = ["-c", "--count"], paramLabel = "COUNT",
              description = "number of repetitions")
      int count = 1
  
      void run() {
  
negative.code: The above will generate the following usage help message, where the `all` field is not shown:
  ----
  Usage: <main class> <host> <port> [<files>...]
        host    destination host
        port    destination port
        files   files to transfer
  ----
  
  === Show Default Values
  