public function createActivity()
    {
        $activity = [];
        $activity['actor'] = $this->activityActor();
        $activity['verb'] = $this->activityVerb();
        $activity['object'] = $this->activityObject();
        $activity['foreign_id'] = $this->activityForeignId();
        $activity['time'] = $this->activityTime();

        $to = $this->activityNotify();

        if ( $to !== null )
        {
            $activity['to'] = [];
            foreach ( $to as $feed )
            {
                $activity['to'][] = $feed->getId();
            }
        }

        $extra_data = $this->activityExtraData();

        if ( $extra_data !== null )
        {
            $activity = array_merge($activity, $extra_data);
        }

        return $activity;
    }