[CLI]ParsedThe parse result: at: reads any declared name (option, positional, rest — a name the spec never declared is a ValueError, so a typo can't read as nil), flag?: a boolean, command the chosen subcommand name (nil without one).
The value under a declared name: an option's String (default applied), a positional's String, the rest-splat's List, a flag's Boolean.
The chosen subcommand's name, or nil when the spec has no commands.
The flag as a Boolean (sugar over at:).
Whether -h/--help was given (the production parse answers it before this is ever seen; parseFrom: callers check it themselves).