Add missing test

Author: veewee

tests/Unit/Multipart/RequestBuilderTest.php

@@ -15,6 +15,18 @@
 
 final class RequestBuilderTest extends TestCase
 {
+    #[Test]
+    public function it_returns_regular_request_on_no_attachments(): void
+    {
+        $storage = new AttachmentStorage();
+        $request = self::createSoapRequest();
+        $builder = RequestBuilder::default();
+
+        $multipartRequest = $builder($request, $storage, AttachmentType::Swa);
+
+        static::assertSame($request, $multipartRequest);
+    }
+
     #[Test]
     public function it_can_build_swa_related_multipart(): void
     {