Final timestamp test

Author: FabioBatSilva

php/tests/extend_timestamp.php

@@ -0,0 +1,13 @@
+<?php
+
+require_once (dirname(__DIR__) . '/vendor/autoload.php');
+
+use Google\Protobuf\Timestamp;
+
+class MyTimestamp extends Timestamp
+{
+}
+
+$t = new MyTimestamp();
+
+var_dump($t->hasSeconds());