private function save(Pair $pair)
    {
        $this->manager->persist($pair);
        $this->manager->commit();
        $this->manager->refresh();
    }
private function save(Pair $pair)
    {
        $this->manager->persist($pair);
        $this->manager->commit();
        $this->manager->refresh();
    }
Saves pair object.

@param Pair $pair