public function get_slot_tags_for_slot_id($slotid) {
        if (!$this->hasloadedtags) {
            // Lazy load the tags just in case they are never required.
            $this->populate_slot_tags();
            $this->hasloadedtags = true;
        }

        return isset($this->slottags[$slotid]) ? $this->slottags[$slotid] : [];
    }