public function getRealDirection($direction)
    {
        if ($direction == 'in' || $direction == 'out')
        {
            $direction = ucfirst($direction);

        } elseif ($direction == 'any')
        {
            $direction = 'All';

        } else
        {
            throw new UnknownDirectionException($direction);
        }

        $direction = "Direction". $direction;

        return constant("Everyman\Neo4j\Relationship::". $direction);
    }