foo.pl

use strict;
use warnings;

{
    package Foo;

    use Moose;

    has foo => (
        is   => 'ro',
        does => 'File::ChangeNotify::Watcher',
    );
}

use Devel::Confess;
use File::ChangeNotify::Watcher::Default;

Foo->new( foo =>
        File::ChangeNotify::Watcher::Default->new( directories => ['~/tmp'] )
);