diff --git a/src/Controller/PluginRevisionController.php b/src/Controller/PluginRevisionController.php
index 07cae4f..23a77fe 100644
--- a/src/Controller/PluginRevisionController.php
+++ b/src/Controller/PluginRevisionController.php
@@ -2,8 +2,11 @@
 
 namespace Drupal\diff\Controller;
 
+use Drupal\Component\Utility\Xss;
+use Drupal\Core\Entity\ContentEntityInterface;
 use Drupal\Core\Entity\EntityInterface;
 use Drupal\Core\Entity\EntityStorageInterface;
+use Drupal\Core\Entity\RevisionLogInterface;
 use Drupal\Core\Routing\RouteMatchInterface;
 use Drupal\Core\Url;
 use Drupal\diff\DiffLayoutManager;
@@ -277,4 +280,17 @@ class PluginRevisionController extends ControllerBase {
     return Url::fromRoute($route_name, $route_parameters);
   }
 
-}
\ No newline at end of file
+  protected function getRevisionDescription(ContentEntityInterface $revision) {
+    $revision_summary = '';
+    if ($revision instanceof RevisionLogInterface) {
+      $revision_summary = Xss::filter($revision->getRevisionLogMessage());
+      if ($revision_summary == '') {
+        // @todo Implement a method to get a revision summary when is none.
+      }
+    }
+    else {
+      // @todo Implement a method to get a revision summary when is none.
+    }
+    return $revision_summary;
+  }
+}