#! /usr/bin/env perl
use 5.020;
use strict;
use warnings;

package DB::Base {
  use Moo;

  has name => (is => 'ro');

  sub option {
    my ( $self, $key ) = @_;
    die('missing key') unless ($key);
    die( 'missing option `' . $key . '`' )
      unless $self->can($key);
    return $self->$key;
  }
}


package DB::Customer {
  use Moo;
  extends 'DB::Base';

  has type     => (is => 'ro', default => 'customer');
  has currency => (is => 'ro', default => 'Euro');
  ...;
}

package main;

my $customer1 = DB::Customer->new(name => 'id_customer 1');

__END__;