Added anonymous/private logic

src/Broker/Topic.php

@@ -29,9 +29,17 @@ class Topic
     public function publish(Message $message)
     {
         // TODO check if message id has already been published
+        if (isset($this->messages[$message->id])) return;
+
+        $this->messages[$message->id] = $message;
+
 
         foreach ($this->subscribers as $subscriber) {
-            // Deliver to all subscribers
+            // Skip sending private messages to unauthorized subscribers
+            if ($message->private && !$subscriber->isAuthorized()) {
+                continue;
+            }
+            // Deliver to the subscriber
             $subscriber->deliver($message);
         }
     }