Mango cursor repeating in non-blocking mode

mango_cursor.pl

use Mango;

use strict;
use warnings;

print "Mango version: $Mango::VERSION\n";

my $mango = Mango->new($ENV{MANGO_URI} // "mongodb://localhost:27017");
my $db = $mango->db('test_db');
my $collection = $db->collection('test_collection');

$collection->remove();

$collection->insert([
    { n => 1 },
    { n => 2 },
    { n => 3 },
]);

my $c = $collection->find({ n => { '$gte' => 0 } });
while(my $doc = $c->next) {
    print $doc->{n};
}
print "\n";

my $c2 = $collection->find({ n => { '$gte' => 0 } });
my $f = 0;
$c2->next(sub {
    my ($collection, $error, $doc) = @_;
    print $doc->{n};
    Mojo::IOLoop->stop if ++$f == 6;
}) for (1..6);

Mojo::IOLoop->start;
print "\n";

output

Mango version: 0.19
123
123123