anchor.diff:  
   
   === Positional Parameters
  -Positional parameters (also called operands) are the command line arguments following the options.
  -
  -Use the (zero-based) `index` attribute to specify exactly which parameters to capture. Omitting the `index` attribute means the field is initialized with all positional parameters (so the field should be a multi-value type like an array or a collection).
  -
  -The `index` attribute accepts _range_ values, so an annotation like `@Parameters(index="2..4")` captures arguments at index 2, 3 and 4. Range values can be _open-ended_. For example, `@Parameters(index="3..*")` captures all arguments from index 3 and up.
  -
  -The advantage of capturing individual parameters in separate fields is that you can enforce strong typing. For example:
  +Positional parameters are the command line arguments following the options.
  +
  +Use the (zero-based) `index` attribute to specify exactly which parameters to capture.
  +Omitting the `index` attribute means the field captures _all_ positional parameters.
  +Array or collection fields can capture multiple values.
  +
  +The `index` attribute accepts _range_ values, so an annotation like `@Parameters(index="2..4")` captures the arguments at index 2, 3 and 4. Range values can be _open-ended_. For example, `@Parameters(index="3..*")` captures all arguments from index 3 and up.
  +
  +For example:
   
   [source,java]
   ----
  
positive.code:     @Option(names = { "-v", "--verbose" }, description = "Be verbose.")
      private boolean verbose = false;
  
      @Option(names = { "-h", "--help" }, help = true,
              description = "Displays this help message and quits.")
      private boolean helpRequested = false;
  
      @Parameters(arity = "1..*", paramLabel = "FILE", description = "File(s) to process.")
      private File[] inputFiles;
      ...
  
negative.code: String[] args = { "-cf", "result.tar", "file1.txt", "file2.txt" };
  Tar tar = CommandLine.parse(new Tar(), args);
  
  assert !tar.helpRequested;
  assert  tar.create;
  assert  tar.archive.equals(new File("result.tar"));
  assert  Arrays.equals(tar.files, new File[] {new File("file1.txt"), new File("file2.txt")});
  ----
  
  Picocli supports http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_02[POSIX clustered short options]:
  One or more options without option-arguments, followed by at most one option with an option-argument, can be grouped behind one '-' delimiter.
  
  
  For example, given this annotated class:
  