Fixing style errors.

src/Event/Event.php

@@ -87,7 +87,7 @@ class Event implements EventInterface
         if (!in_array($attribute, ['name', 'subject', 'data', 'result'])) {
             return $this->{$attribute};
         }
-        
+
         $method = 'get' . ucfirst($attribute);
         deprecationWarning(
             "Event::\${$attribute} is deprecated. " .