def run(argv = ARGV)
      history << [filename] + argv
      output = @outputs[argv] || @default_output
      puts output[:puts] if output[:puts]
      warn output[:warn] if output[:warn]
      exit output[:exit] if output[:exit]
    end
def run(argv = ARGV)
      history << [filename] + argv
      output = @outputs[argv] || @default_output
      puts output[:puts] if output[:puts]
      warn output[:warn] if output[:warn]
      exit output[:exit] if output[:exit]
    end
Run the double.

 This will append the call to the doubles history, display any
 outputs if defined and exit.