/** * @param UserInterface $user * @return array */ public function serialize(UserInterface $user) { $serialized = ['user_id' => $user->getUserId(), 'email' => $user->getEmail(), 'name' => $user->getName()]; $signedUpAt = $user->getSignedUpAt(); if (null !== $signedUpAt) { $serialized['signed_up_at'] = $signedUpAt->getTimestamp(); } return $serialized; }