role {
    my $param = shift;
    my $NAME = $param->name;
    my $ROOT = $param->root;
    my $MODEL = $param->model_name;
    my $PATH_PART = $param->path_part;

    method model => sub { $_[1]->model( $MODEL ) };
    method root => sub { ... };
    method list => sub {...};

    # The purpose of this 'before' is to add keys
    # into config hash first (only first) time the config is touched.
    my $config_called;
    before config => sub {
        return if $config_called++;

        my $action_config = shift()->config->{action} ||= {};
        %$action_config = (
            %$action_config,
            root => {
                Chained     => [$ROOT],
                PathPart    => [$PATH_PART],
                CaptureArgs => [0],
            },

            list => {
                Chained  => ['root'],
                PathPart => [''],
                Args     => [0],
            }
        );
    };
};