View file vendor/laravel/framework/src/Illuminate/Contracts/Queue/QueueableEntity.php
<?php namespace Illuminate\Contracts\Queue; interface QueueableEntity { /** * Get the queueable identity for the entity. * * @return mixed */ public function getQueueableId(); /** * Get the relationships for the entity. * * @return array */ public function getQueueableRelations(); /** * Get the connection of the entity. * * @return string|null */ public function getQueueableConnection(); }