anchor.diff:  
   . Call it:
   +
  ++
  +.Show help
   ----
   $ ./myscript --help
   SYNOPSIS:
   myscript --greet <number> [--debug] [--help|-h|-?] [--list <lang=msg>...]...
   
   REQUIRED PARAMETERS:
  -    --greet <number>             Number of times to greet. 
  +    --greet <number>             Number of times to greet.
   
   OPTIONS:
       --debug                      (default: false)
  
positive.code: 
  ----
  +
  ----
  $ ./myscript 
  ERROR: Missing required option 'greet'!
  
  SYNOPSIS:
  myscript --greet <number> [--debug] [--help|-h|-?] [--list <lang=msg>...]...
  ----
  +
  ----
  $ ./myscript -g
  ERROR: Missing argument for option 'greet'!
  
negative.code: myscript --greet <number> [--debug] [--help|-h|-?] [--list <lang=msg>...]...
  ----
  +
  .Use of int option
  ----
  $ ./myscript -g 3
  Hello World, from go-getoptions!
  