```console $ 04_01_possible --help A simple to use, efficient, and full-featured Command Line Argument Parser Usage: 04_01_possible[EXE] Arguments: What mode to run the program in [possible values: fast, slow] Options: -h, --help Print help information -V, --version Print version information $ 04_01_possible fast Hare $ 04_01_possible slow Tortoise $ 04_01_possible medium ? failed error: "medium" isn't a valid value for '' [possible values: fast, slow] For more information try --help ```