use v5.12;

{
	package Backpack;
	use Moose;
	
	has colour => (
		accessor  => 'colour',
		writer    => 'paint',
		default   => sub { 'black' },
	);
	
	has contents => (
		traits    => ['Array'],
		accessor  => 'contents',
		default   => sub { [] },
		handles   => {
			add_item => 'push',
			is_empty => 'is_empty',
		},
	);
}

my $x = Backpack->new(colour => "Red");
$x->add_item("keys");
$x->add_item("mobile phone");
$x->add_item("mobile phone charger");

my $y = Backpack->new(contents => ["pants"]);

print $x->dump, $y->dump;