#!/usr/bin/perl -w

{
  package IO::Dir::pl;
  use strict; use warnings;
  our @ISA;
  @ISA = qw(IO::Dir);

  sub read{
    my $self = shift;
    warn "Ok We got here.\n";
    return undef;
  }
}

use strict;
use warnings;
use IO::Dir;
my $dh = IO::Dir::pl->new('.');
while (my $file_name = $dh->read()){
    print STDOUT "$file_name\n";
    exit;
}

> /tmp/p
Ok We got here.