fix tests

src/test/java/de/ozgcloud/eingang/semantik/enginebased/afm/intelliform/XmlToJavaMapsMapperTest.java

@@ -49,8 +49,13 @@ class XmlToJavaMapsMapperTest {
 	@Mock
 	private JsonService jsonService;
 
-	private final Document document = mapper.parseAsW3cDocument(
+	private Document document;
+
+	@BeforeEach
+	void beforeEach() {
+		document = mapper.parseAsW3cDocument(
 				XmlToJavaMapsMapperTest.class.getResourceAsStream("/intelliform/SimpleFormDataMapperTestFile.xml"));
+	}
 
 	@Test
 	void testSimpleNode() {