/**
  * The getCampaignZoneStatistics method returns zone statistics for a campaign
  * for a specified period.
  *
  * @access public
  *
  * @param string $sessionId
  * @param integer $campaignId
  * @param date $oStartDate
  * @param date $oEndDate
  * @param recordSet &$rsStatisticsData  return data
  *
  * @return boolean
  */
 function getCampaignZoneStatistics($sessionId, $campaignId, $oStartDate, $oEndDate, &$rsStatisticsData)
 {
     if ($this->verifySession($sessionId)) {
         return $this->_validateResult($this->_dllCampaign->getCampaignZoneStatistics($campaignId, $oStartDate, $oEndDate, false, $rsStatisticsData));
     } else {
         return false;
     }
 }