Adding deprecation warnings to the Rss and SessionHelper

src/View/Helper/RssHelper.php

@@ -14,6 +14,8 @@
  */
 namespace Cake\View\Helper;
 
+deprecationWarning('RssHelper is deprecated and will be removed in 4.0.0');
+
 use Cake\Utility\Xml;
 use Cake\View\Helper;
 

src/View/Helper/SessionHelper.php

@@ -14,6 +14,11 @@
  */
 namespace Cake\View\Helper;
 
+deprecationWarning(
+    'SessionHelper is deprecated and will be removed in 4.0.0. ' .
+    'Use request->session() instead.'
+);
+
 use Cake\View\Helper;
 use Cake\View\View;
 

tests/TestCase/View/Helper/RssHelperTest.php

@@ -41,8 +41,14 @@ class RssHelperTest extends TestCase
     public function setUp()
     {
         parent::setUp();
+
+        $errorLevel = error_reporting();
+        error_reporting(E_ALL ^ E_USER_DEPRECATED);
+
         $this->View = new View();
         $this->Rss = new RssHelper($this->View);
+
+        error_reporting($errorLevel);
     }
 
     /**