sub walk_oo_tree
{
    my $obj = shift;

    my $class = ref $obj ? ref $obj : $obj;

    my @class_list = ();

    unless ($skip_class_map{$class})
    {
        NO_STRICT_REFS_ZONE:
        {
            no strict 'refs';
            @class_list = ($class, map { @{walk_oo_tree($_)} } @{join('::', $class, 'ISA')});
            use strict 'refs';
        }
    }

    return \@class_list;
}