Почему returnValueMap() возвращает NULL

Пытаясь имитировать репозиторий доктрин внутри теста, returnValueMap() всегда возвращает NULL при использовании с методом найтиOneBy.

Я издевался над двумя объектами, а затем пытался издеваться над их репозиторием с заданной картой возвращаемых значений. Тест не пройден, и отладка показывает, что returnValueMap() возвращает NULL.

Вот тестируемый класс (денормализатор)

<?php

declare(strict_types=1);

namespace App\Serializer;

use App\Entity\AdditionalService;
use App\Repository\AdditionalServiceRepository;
use Dto\AdditionalServiceCollection;
use Symfony\Component\Serializer\Normalizer\DenormalizerInterface;

class AdditionalServiceCollectionDenormalizer implements DenormalizerInterface
{
    /** @var AdditionalServiceRepository */
    private $additionalServiceRepository;

    public function __construct(AdditionalServiceRepository $additionalServiceRepository)
    {
        $this->additionalServiceRepository = $additionalServiceRepository;
    }

    public function denormalize($mappedCsvRow, $class, $format = null, array $context = [])
    {
        $addtionalServicesCollection = new AdditionalServiceCollection();
        foreach ($mappedCsvRow as $fieldName => $fieldValue) {
            /** @var AdditionalService $additionalService */
            $additionalService = $this->additionalServiceRepository->findOneBy(['name'=>$fieldName]);

            if ($additionalService) {
                $addtionalServicesCollection->add($additionalService->getId(), $fieldValue);
            }
        }

        return $addtionalServicesCollection;
    }

    public function supportsDenormalization($data, $type, $format = null)
    {
        return $type instanceof  AdditionalServiceCollection;
    }
}

Вот мой тестовый класс:

<?php

namespace App\Tests\Import\Config;

use App\Entity\AdditionalService;
use App\Repository\AdditionalServiceRepository;
use App\Serializer\AdditionalServiceCollectionDenormalizer;
use PHPUnit\Framework\TestCase;
use Dto\AdditionalServiceCollection;

class AddionalServiceCollectionDenormalizerTest extends TestCase
{
    public function provider()
    {
        $expected = new AdditionalServiceCollection();
        $expected->add(1, 22.1)->add(2, 3.1);

        return [
            [['man_1' => 22.1], $expected],
            [['recycling' => 3.1], $expected],
        ];
    }

    /**
     * @dataProvider provider
     * @covers \App\Serializer\AdditionalServiceCollectionDenormalizer::denormalize
     */
    public function testDenormalize(array $row, AdditionalServiceCollection $exptected)
    {
        $manOneService = $this->createMock(AdditionalService::class);
        $manOneService->expects($this->any())->method('getId')->willReturn(1);

        $recycling = $this->createMock(AdditionalService::class);
        $recycling->expects($this->any())->method('getId')->willReturn(2);

        $additionalServicesRepoMock = $this
            ->getMockBuilder(AdditionalServiceRepository::class)
            ->setMethods(['findOneBy'])
            ->disableOriginalConstructor()
            ->getMock();
        $additionalServicesRepoMock
            ->expects($this->any())
            ->method('findOneBy')
            ->will($this->returnValueMap(
                [
                    ['name'=>['man_1'], $manOneService],
                    ['name'=>['recycling'], $recycling],
                ]
            ));

        $denormalizer = new AdditionalServiceCollectionDenormalizer($additionalServicesRepoMock);

        self::assertEquals($exptected, $denormalizer->denormalize($row, AdditionalServiceCollection::class));
    }
}