sub list_params {
    my ( $self, $cgi ) = @_;
    my %formdata;
    $cgi = CGI::self_or_default if ( ! defined $cgi or ! ref $cgi ) and $cgi;

    if ( defined $cgi and $cgi ) {
        foreach my $key ( $cgi->param ) {
            my @vals = $cgi->param( $key );
            $formdata{ $key } = _format_vals( \@vals );
        }
    } else {
        return 0;
    }
    Dumper( \%formdata );
}