>>>
greet(@Rest(valueHelp: 'who', help: 'Name(s) to greet.') List<String> who,
    {@Group.start(title: 'Output')
    @Option(help: 'How many !\'s to append.')
    int enthusiasm: 0,
    @Flag(abbr: 'l', help: 'Put names on separate lines.') bool lineMode: false,
    @Option(name: 'greeting', help: 'Alternate word to greet with e.g. "Hi".')
    String salutation: 'Hello'}) {}
<<<
greet(
    @Rest(valueHelp: 'who', help: 'Name(s) to greet.')
        List<String> who,
    {@Group.start(title: 'Output')
    @Option(help: 'How many !\'s to append.')
        int enthusiasm: 0,
    @Flag(abbr: 'l', help: 'Put names on separate lines.')
        bool lineMode: false,
    @Option(name: 'greeting', help: 'Alternate word to greet with e.g. "Hi".')
        String salutation: 'Hello'}) {}