use Moops;

class Cat :ro {
	has name => (isa => Str);
}

class Litter :ro {
	has cats => (isa => ArrayRef[InstanceOf['Cat']]);
}

my $cat1   = Cat->new(name=>'Garfield');
my $cat2   = Cat->new(name=>'Felix');
my $litter = Litter->new(cats => [$cat1, $cat2, 1]);