main' :: Flag "b" '["bool"] "STRING" "boolean flag" Bool
      -> Cmd "Simple greeting example" ()
main' b =
    liftIO $ putStrLn $ if get b then "Flag is True" else "Flag is False"
main' :: Flag "b" '["bool"] "STRING" "boolean flag" Bool
      -> Cmd "Simple greeting example" ()
main' b =
    liftIO $ putStrLn $ if get b then "Flag is True" else "Flag is False"
main' b =
    liftIO $ putStrLn $ if get b then "Flag is True" else "Flag is False"