app/bundles/EmailBundle/Stats/Helper/StatHelperInterface.php

<?php

namespace Mautic\EmailBundle\Stats\Helper;

use Mautic\EmailBundle\Stats\FetchOptions\EmailStatOptions;
use Mautic\StatsBundle\Aggregate\Collection\StatCollection;

interface StatHelperInterface
{
    /**
     * @return string
     */
    public function getName();

    public function fetchStats(\DateTime $fromDateTime, \DateTime $toDateTime, EmailStatOptions $options);

    public function generateStats(\DateTime $fromDateTime, \DateTime $toDateTime, EmailStatOptions $options, StatCollection $statCollection);
}