package Local::TShirt {
      use Moose;
      use Types::Common -types;
      use Type::Tiny::Enum Size => [ qw( S M L XL ) ];
      use namespace::autoclean;
      
      has size => (
         is        => 'ro',
         isa       => Size,
         required  => 1,
      );
      
      sub price {
         my $self = shift;
         my $size = $self->size;
         
         if ( $size eq SIZE_XL ) {
            return 10.99;
         }
         elsif ( $size eq SIZE_L ) {
            return 9.99;
         }
         else {
            return 8.99;
         }
      }
   }