public function compare(Length $measurement)
 {
     $diff = Comparable::GREATER_THAN;
     if ($measurement->isLessThan($this->getStart())) {
         $diff = Comparable::LESS_THAN;
     } elseif ($measurement->isLessThan($this->getEnd())) {
         $diff = Comparable::EQUAL_TO;
     }
     return (int) $diff;
 }