Doctrine orm 索纳塔媒体多张照片下载

我正在尝试通过sonata CollectionType下载多张照片
机械实体：

     * @var MechanicWorkImage
     *
     * @ORM\OneToMany(targetEntity="MechanicWorkImage", mappedBy="mechanic", cascade={"all"},  orphanRemoval=true, fetch="EAGER")
     */
    protected $workPhotos;

 $formMapper->tab('Work Photos')
            ->with('')
            ->add(
                'workPhotos',
                CollectionType::class,
                [
                    'by_reference' => false,
                    'label' => 'Work Photos',
                    'required' => true,
                ],
                [
                    'edit' => 'inline',
                    'inline' => 'table',
                ]
            )
            ->end()

机械工作图像实体

     * @var SonataMediaMedia
     *
     * @Assert\NotBlank()
     * @ORM\ManyToOne(targetEntity="App\Entity\SonataMediaMedia", cascade={"persist"}, fetch="EAGER")
     * @ORM\JoinColumn(name="media_id", referencedColumnName="id", onDelete="CASCADE")
     */
    protected $media;

    /**
     * @var Mechanic
     * @Assert\NotBlank()
     * @ORM\ManyToOne(targetEntity="App\Entity\Mechanic", cascade={"persist","remove"} ,inversedBy="workPhotos", fetch="LAZY")
     * @ORM\JoinColumn(name="mechanic_id", referencedColumnName="id", nullable=false, onDelete="CASCADE")
     */
    protected $mechanic;

和机械管理员：

     * @var MechanicWorkImage
     *
     * @ORM\OneToMany(targetEntity="MechanicWorkImage", mappedBy="mechanic", cascade={"all"},  orphanRemoval=true, fetch="EAGER")
     */
    protected $workPhotos;

 $formMapper->tab('Work Photos')
            ->with('')
            ->add(
                'workPhotos',
                CollectionType::class,
                [
                    'by_reference' => false,
                    'label' => 'Work Photos',
                    'required' => true,
                ],
                [
                    'edit' => 'inline',
                    'inline' => 'table',
                ]
            )
            ->end()

在输出中，我什么都没有：