anchor.diff:  
   > a mighty tiny command line processor
   
  +
  +image:images/logo/horizontal.png[picocli a Mighty Tiny Command Line Interface]
  +
  +
   Picocli is a one-file framework for creating JVM command line applications (in Java, Groovy, Kotlin, Scala, etc.) with almost zero code.
   It has an annotations API and a programmatic API, and features usage help with ANSI colors, command line autocompletion and support for nested subcommands.
   Its source code lives in a single file, so you have the option to include it in source form; this lets end users run picocli-based applications without requiring picocli as an external dependency.
  
positive.code: To generate a completion script, we call `picocli.AutoComplete`, and give it the name of the class and the name of the command:
  [source,bash]
  ----
  java -cp "checksum-1.0.jar:picocli-3.9.5.jar" picocli.AutoComplete -n jchecksum com.example.CheckSum
  ----
  
  This will generate a file called `jchecksum_completion` in the current directory.
  
negative.code: ----
  @Grab('info.picocli:picocli:3.9.5')
  @Command(header = [
   $/@|green    ___                            ___ _           _                  |@/$,
   $/@|green   / __|_ _ ___  _____ ___  _     / __| |_  ___ __| |__ ____  _ _ __  |@/$,
   $/@|green  | (_ | '_/ _ \/ _ \ V / || |   | (__| ' \/ -_) _| / /(_-< || | '  \ |@/$,
   $/@|green   \___|_| \___/\___/\_/ \_, |    \___|_||_\___\__|_\_\/__/\_,_|_|_|_||@/$,
   $/@|green                         |__/                                         |@/$
   ],
      description = "Print a checksum of each specified FILE.",
      mixinStandardHelpOptions = true, version = 'gchecksum v1.2.3', showDefaultValues = true,
      footerHeading = "%nFor more details, see:%n",
      footer = ["[1] https://docs.oracle.com/javase/9/docs/specs/security/standard-names.html",
              "ASCII Art thanks to http://patorjk.com/software/taag/"]
  )
  @picocli.groovy.PicocliScript
  import groovy.transform.Field
  