Pinq\ITraversable::difference PHP Метод

    public function difference($values);

 public function visitOperation(Segments\Operation $query)
 {
     $otherValues = self::evaluateSource($query->getSource(), $this->resolvedParameters);
     switch ($query->getOperationType()) {
         case Segments\Operation::UNION:
             $this->traversable = $this->traversable->union($otherValues);
             break;
         case Segments\Operation::INTERSECT:
             $this->traversable = $this->traversable->intersect($otherValues);
             break;
         case Segments\Operation::DIFFERENCE:
             $this->traversable = $this->traversable->difference($otherValues);
             break;
         case Segments\Operation::APPEND:
             $this->traversable = $this->traversable->append($otherValues);
             break;
         case Segments\Operation::WHERE_IN:
             $this->traversable = $this->traversable->whereIn($otherValues);
             break;
         case Segments\Operation::EXCEPT:
             $this->traversable = $this->traversable->except($otherValues);
             break;
     }
 }