/**
  * @param \DateTime $date
  * @param ActivityDayCollection $collection
  * @return integer
  */
 private function calculateTotalCountByCollection(\DateTime $date, $collection)
 {
     $return = 0;
     $subjectCollection = $collection->getByDate($date);
     if (!is_null($subjectCollection)) {
         $return = $subjectCollection->totalCount();
     }
     return $return;
 }