Include vendor directory

vendor/maennchen/zipstream-php/test/Zs/ExtendedInformationExtraFieldTest.php

@@ -0,0 +1,22 @@
+<?php
+
+declare(strict_types=1);
+
+namespace ZipStream\Test\Zs;
+
+use PHPUnit\Framework\TestCase;
+use ZipStream\Zs\ExtendedInformationExtraField;
+
+class ExtendedInformationExtraFieldTest extends TestCase
+{
+    public function testSerializesCorrectly(): void
+    {
+        $extraField = ExtendedInformationExtraField::generate();
+
+        $this->assertSame(
+            bin2hex((string) $extraField),
+            '5356' . // 2 bytes; Tag for this "extra" block type
+            '0000' // 2 bytes; TODO: Document
+        );
+    }
+}