anchor.diff:  execution of the command. This makes it easier to break up large run blocks
   into manageable pieces.
   
  +=== Subcommands ===
  +
   Commands can have subcommands. For example, the `git` commandline tool would be
   represented by a command that has subcommands named `commit`, `add`, and so on.
   Commands with subcommands do not use a run block; execution will always be
  
positive.code:     -s --stuff     specify stuff to do
  --------------------------------------------------------------------------------
  
  Let’s disect the command definition and start with the first five lines:
  
  [source,ruby]
  
negative.code: flag :v, :verbose, 'be verbose (use up to three times)', multiple: true
  --------------------------------------------------------------------------------
  
  === The run block ===
  
  The last part of the command defines the execution itself:
  
  [source,ruby]
  