Try to fix test

Author: Jean85

tests/Gedmo/Timestampable/TimestampableDocumentTest.php

@@ -16,6 +16,7 @@
 use Gedmo\Tests\Timestampable\Fixture\Document\Type;
 use Gedmo\Tests\Tool\BaseTestCaseMongoODM;
 use Gedmo\Timestampable\TimestampableListener;
+use MongoDB\BSON\Timestamp;
 
 /**
  * These are tests for Timestampable behavior ODM implementation
@@ -41,7 +42,11 @@ public function testTimestampable(): void
 
         $date = new \DateTime();
         $now = time();
-        $created = $article->getCreated()->getTimestamp();
+        $created = $article->getCreated();
+        if ($created instanceof Timestamp) {
+            $created = $created->getTimestamp();
+        }
+
         static::assertTrue($created > $now - 5 && $created < $now + 5); // 5 seconds interval if lag
         static::assertSame(
             $date->format('Y-m-d H:i'),
@@ -80,10 +85,12 @@ public function testForcedValues(): void
 
         $repo = $this->dm->getRepository(Article::class);
         $sport = $repo->findOneBy(['title' => 'sport forced']);
-        static::assertSame(
-            $created,
-            $sport->getCreated()->getTimestamp()
-        );
+        $createdField = $sport->getCreated();
+        if ($createdField instanceof Timestamp) {
+            $createdField = $createdField->getTimestamp();
+        }
+
+        static::assertSame($created, $createdField);
         static::assertSame(
             '2000-01-01 12:00:00',
             $sport->getUpdated()->format('Y-m-d H:i:s')