#!/usr/bin/perl
use warnings;
use strict;
use Cpanel::JSON::XS;

{
    package My::Package;
    use Moose;
    has attr => ( is => 'ro', isa => 'Bool' );

    __PACKAGE__->meta->make_immutable;
}

my $obj = 'My::Package'->new(attr => Cpanel::JSON::XS::true());