You might be interested in Subclass::Of, an idea I've been working on recently...

#!/usr/bin/env perl

use strict;
use warnings;

use Subclass::Of "IO::Dir",
    -as      => "My_IO_Dir",
    -methods => [
        read_pl => sub {
            my $self = shift;
            warn "Ok We got here.\n";
            return undef;
        },
    ];

my $dh = My_IO_Dir->new('.');

while (my $file_name = $dh->read_pl()) {
    print STDOUT "$file_name\n";
}
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