/**
     * @ORM\Id
     * @ORM\GeneratedValue(strategy="IDENTITY")
     * @ORM\Column(type="integer")
     */
    protected $id;

<?php

namespace App\Repository;

use App\Entity\ShortUrl;
use Doctrine\Bundle\DoctrineBundle\Repository\ServiceEntityRepository;
use Symfony\Bridge\Doctrine\RegistryInterface;

/**
 * @method ShortUrl|null find($id, $lockMode = null, $lockVersion = null)
 * @method ShortUrl|null findOneBy(array $criteria, array $orderBy = null)
 * @method ShortUrl[]    findAll()
 * @method ShortUrl[]    findBy(array $criteria, array $orderBy = null, $limit = null, $offset = null)
 */
class ShortUrlRepository extends ServiceEntityRepository
{
    public function __construct(RegistryInterface $registry)
    {
        parent::__construct($registry, ShortUrl::class);
    }
}

/**
 * Class TestEntity
 * @package LTree\Entity
 *
 * @Entity(repositoryClass="App\Infrastructure\Repository\TestRepository")
 * @LTreeEntity()
 */
class TestEntity implements LTreeEntityInterface
{ ...

<?php

namespace App\Infrastructure\Repository;

use Doctrine\ORM\EntityManagerInterface;
use LTree\Repository\LTreeEntityRepository;
use App\Domain\Ltree\TestEntity;

/**
 * Class TestRepository
 *
 * @method TestEntity|null find($id, $lockMode = null, $lockVersion = null)
 * @method TestEntity|null findOneBy(array $criteria, array $orderBy = null)
 * @method TestEntity[]    findAll()
 * @method TestEntity[]    findBy(array $criteria, array $orderBy = null, $limit = null, $offset = null)
 *
 * @package LTree\Entity
 */
class TestRepository extends LTreeEntityRepository
{
    /**
     * TestRepository constructor.
     * @param EntityManagerInterface $registry
     */
    public function __construct(EntityManagerInterface $registry)
    {
        parent::__construct($registry, $registry->getClassMetadata(TestEntity::class));
    }
}

<?php
namespace App\Infrastructure\Repository;

use App\Infrastructure\TestCase\ContainerTestCase;
use App\Domain\Ltree\TestEntity;

/**
 * Class TestRepositoryTest
 * @package App\Infrastructure\Repository
 */
class TestRepositoryTest extends ContainerTestCase
{
    /**
     * @var TestRepository
     */
    private $repo;

    /**
     * @inheritdoc
     */
    protected function setUp(): void
    {
        parent::setUp();
        
        // it's the same as to call $this->getContainer()->get('doctrine')->getManager()->getRepository(...)
        $this->repo = $this->getRepository('Ltree:TestEntity');
    }

    /**
     * @return void
     */
    public function testGetSuccess()
    {
        $node = $this->repo->get(2);

        $this->assertInstanceOf(TestEntity::class, $node);
    }
}