key() public method

public key ( )
 /**
  * @param Client $client
  * @return array
  */
 public function transform(Activity $activity)
 {
     return ['id' => $activity->key(), 'activity_type_id' => $activity->activity_type_id, 'client_id' => $activity->client->public_id, 'user_id' => $activity->user->public_id + 1, 'invoice_id' => $activity->invoice ? $activity->invoice->public_id : null, 'payment_id' => $activity->payment ? $activity->payment->public_id : null, 'credit_id' => $activity->credit ? $activity->credit->public_id : null, 'updated_at' => $this->getTimestamp($activity->updated_at)];
 }
 /**
  * @param Activity $activity
  * @return array
  */
 public function transform(Activity $activity)
 {
     return ['id' => $activity->key(), 'activity_type_id' => $activity->activity_type_id, 'client_id' => $activity->client ? $activity->client->public_id : null, 'user_id' => $activity->user->public_id + 1, 'invoice_id' => $activity->invoice ? $activity->invoice->public_id : null, 'payment_id' => $activity->payment ? $activity->payment->public_id : null, 'credit_id' => $activity->credit ? $activity->credit->public_id : null, 'updated_at' => $this->getTimestamp($activity->updated_at), 'expense_id' => $activity->expense_id ? $activity->expense->public_id : null, 'is_system' => (bool) $activity->is_system ? $activity->is_system : null, 'contact_id' => $activity->contact_id ? $activity->contact->public_id : null];
 }