protected function get_first_start() {
        global $DB;

        $cache = \cache::make('core', 'modelfirstanalyses');

        $key = $this->modelid . '_' . $this->analysable->get_id();
        $firstanalysis = $cache->get($key);
        if (!empty($firstanalysis)) {
            return $firstanalysis;
        }

        // This analysable has not yet been analysed, the start is therefore now (-1 so ready_to_predict can be executed).
        return time() - 1;
    }