How to use Timestampable in a Trait with Platform API groups

Now i have a lot of entities with:

#[ORM\Column(type: 'datetime')]
#[Groups(['article_category:output'])]
/**
 * @Timestampable(on="create")
 */
private \DateTime $createdAt;

public function getCreatedAt(): \DateTime
{
    return $this->createdAt;
}

And i want to put it inside Trait. But each entity has its own normalization group (like 'article_category:output'). How can I make this field always available from the API Platform?

What we did:

use a group in your trait, e.g. timestampable

trait TimestampableEntity
{
    /**
     * ...
     * @Groups({"timestampable"})
     */
    protected $createdAt;

    ...
}

Then whenever you want to expose the timestamps, add them to your config (you can add multiple groups to an operation)

<?php
/**
 * @ApiResource(
 *     collectionOperations= {
 *          "get" = {
 *              "normalization_context"={"groups"={"appointment:read", "timestampable"}},
 *           },
 *     },
 * )
 */
class Appointment
{
    use TimestampableEntity;