Fix missingType.return errors

Author: warcooft

system/Test/Mock/MockSession.php

@@ -38,7 +38,7 @@ class MockSession extends Session
      * Sets the driver as the session handler in PHP.
      * Extracted for easier testing.
      */
-    protected function setSaveHandler()
+    protected function setSaveHandler(): void
     {
         // session_set_save_handler($this->driver, true);
     }
@@ -47,7 +47,7 @@ protected function setSaveHandler()
      * Starts the session.
      * Extracted for testing reasons.
      */
-    protected function startSession()
+    protected function startSession(): void
     {
         // session_start();
         $this->setCookie();
@@ -57,15 +57,15 @@ protected function startSession()
      * Takes care of setting the cookie on the client side.
      * Extracted for testing reasons.
      */
-    protected function setCookie()
+    protected function setCookie(): void
     {
         $expiration   = $this->config->expiration === 0 ? 0 : Time::now()->getTimestamp() + $this->config->expiration;
         $this->cookie = $this->cookie->withValue(session_id())->withExpires($expiration);
 
         $this->cookies[] = $this->cookie;
     }
 
-    public function regenerate(bool $destroy = false)
+    public function regenerate(bool $destroy = false): void
     {
         $this->didRegenerate              = true;
         $_SESSION['__ci_last_regenerate'] = Time::now()->getTimestamp();