change function type in payload.

laravel/session/payload.php

@@ -23,18 +23,18 @@ class Payload {
 	public $session;
 
 	/**
-	 * Indicates if the session already exists in storage.
+	 * The session driver used to retrieve and store the session payload.
 	 *
-	 * @var bool
+	 * @var Driver
 	 */
-	protected $exists = true;
+	public $driver;
 
 	/**
-	 * The session driver used to retrieve and store the session payload.
+	 * Indicates if the session already exists in storage.
 	 *
-	 * @var Driver
+	 * @var bool
 	 */
-	protected $driver;
+	public $exists = true;
 
 	/**
 	 * Create a new session payload instance.