package Checkout;

    # $Id$
    #

    use strict;
    use warnings;

    our $VERSION = '0.01';

    use Moose;
    use Readonly;

    Readonly::Scalar our $PRICE_OF_A => 50;

    sub price {
        my ( $self, $items ) = @_;

        if ( defined $items ) {
            $self->{price} = 0;

            if ( $items eq 'A' ) {
                $self->{price} = $PRICE_OF_A;
            }
        }

        return $self->{price};
    }

    __PACKAGE__->meta->make_immutable;

    no Moose;

    1;