Update Worker.php

src/Worker.php

@@ -2131,7 +2131,7 @@ class Worker
      * @param string $socket_name
      * @param array $context_option
      */
-    public function __construct(string $socket_name = '', array $context_option = [])
+    public function __construct(string $socket_name = null, array $context_option = [])
     {
         // Save all worker instances.
         $this->workerId = \spl_object_hash($this);