anchor.diff:  
   
   == Multiple Values
  -Multi-valued options and positional parameters can capture multiple values from the command line.
  +Multi-valued options and positional parameters are annotated fields that can capture multiple values from the command line.
   
   === Multiple Occurrences
   The simplest way to create a multi-valued option is to declare an annotated field whose type is an array, collection or a map.
  
positive.code:     private boolean helpRequested;
  
      public static void main(String[] args) throws Exception {
          // CheckSum implements Callable,
          // so parsing and error handling can be done in one line of code
          CommandLine.call(new CheckSum(), System.err, args);
      }
  
      @Override
      public Void call() throws Exception {
          if (helpRequested) {
              CommandLine.usage(this, System.err);
              return null;
          }
          byte[] fileContents = Files.readAllBytes(file.toPath());
          byte[] digest = MessageDigest.getInstance(algorithm).digest(fileContents);
          System.out.println(javax.xml.bind.DatatypeConverter.printHexBinary(digest));
  
negative.code: adding subcommands.
  
  === Registering Subcommands Declaratively
  From v0.9.8, picocli supports registering subcommands declaratively with the `@Command` annotation's `subcommands` attribute.
  
  [source,java]
  ----
  