use strict;
use warnings;
use Test::More;
use Test::Moose;
{
    package Foo;
    use Moose;
    has foo => (
        is        => 'ro',
        isa       => 'Maybe[Int]',
        default   => undef,
        predicate => 'has_foo',
    );
}
with_immutable {
    is(Foo->new->foo, undef);
    ok(Foo->new->has_foo);
} 'Foo';
done_testing;