package Pixie::ObjectInfo;
...
sub DESTROY {
    ...
    $self->store->unlock($self);
}

package Pixie;

sub get {
    my $self = shift;
    my $object_id = shift;
    my $obj = $self->really_get($object_id);
    $obj->{__Pixie} = Pixie::ObjectInfo->new(oid => $object_id);
}