/**
  * @param int $paceInSeconds
  * @return int
  */
 protected function zoneFor($paceInSeconds)
 {
     if ($paceInSeconds == 0) {
         return 0;
     }
     if ($this->PaceUnit->isDecimalFormat()) {
         $dividend = $this->PaceUnit->dividendForUnit();
         return $paceInSeconds > $dividend ? 0 : $dividend / floor($dividend / $paceInSeconds);
     }
     $factor = $this->PaceUnit->factorForUnit();
     return round(30 * floor($factor * $paceInSeconds / 30) / $factor);
 }