Moose и современная модель объектов

package User;
use Moose;
has 'name' => (is => 'ro', isa => 'Str', required => 1);

package Listener;
use Moose;
has 'port' => (is => 'ro', isa => 'Int');

package Loggable;
use Moose::Role;
requires 'logger';
sub log_event {
    my ($self, $message) = @_;
    $self->logger->info($message);
}

package Record;
use Moose;
has 'id' => (is => 'ro', isa => 'Str', required => 1);
__PACKAGE__->meta->make_immutable;

package Job;
use Moose;
has 'command' => (is => 'ro', isa => 'ArrayRef[Str]', required => 1);
sub run {
    my ($self) = @_;
    return system @{ $self->command };
}

__PACKAGE__->meta->make_immutable;

package CacheOwner;
use Moose;
has 'cache' => (is => 'rw', default => {});

package Source;
use Moose;
has 'path' => (is => 'ro', isa => 'Str', required => 1);
sub open_path {
    my ($self) = @_;
    open my $fh, '<', $self->path or die $!;
    return $fh;
}

package Worker;
use Moose;
with 'RoleA', 'RoleB';    # обе роли предоставляют run

$obj->{id}='other';

package PluginLoader;
use Moose;
has 'module' => (is => 'ro', isa => 'Str', required => 1);
sub load_module {
    my ($self) = @_;
    my $module = $self->module;
    eval "require $module; 1" or die $@;
}

package Report;
use Moose;
has 'data' => (is => 'ro', default => sub { load_huge() });

package CacheOwner;
use Moose;
has 'cache' => (is => 'rw', default => sub { {} });

use Moose::Util::TypeConstraints;
subtype 'Port',
    as 'Int',
    where { $_ >= 1 && $_ <= 65_535 };

package Worker;
use Moose;
with 'RoleA' => {
    -alias    => { run => 'run_a' },
    -excludes => 'run',
};

package Basket;
use Moose;
has 'items' => (is => 'ro', isa => 'ArrayRef[Str]', required => 1);
around BUILDARGS => sub {
    my ($orig, $class, %args) = @_;
    die 'items must be an array' if ref($args{items}) ne 'ARRAY';
    $args{items} = [ @{ $args{items} } ];
    return $class->$orig(%args);
};

use Moose::Util::TypeConstraints;
enum 'Plugin' => [qw(csv json xml)];

package Report;
use Moose;
has 'data' => (
    is      => 'ro',
    lazy    => 1,
    builder => '_build_data',
);