OZG-6239 add XtaMessageRepositoryTest::shouldDeleteMessage

also code style

src/test/java/de/ozgcloud/xta/test/app/data/XtaMessageRepositoryTest.java

@@ -87,6 +87,13 @@ public class XtaMessageRepositoryTest {
 			xtaMessageRepository.save(message);
 		}
 
+		@Test
+		void shouldDeleteMessage() {
+			xtaMessageRepository.delete(MESSAGE_ID);
+
+			assertThat(xtaMessageRepository.get(MESSAGE_ID)).isEmpty();
+		}
+
 		@Test
 		void shouldDeleteTemporaryFiles() {
 			assertThat(messageFile.file()).exists();

src/test/java/de/ozgcloud/xta/test/app/factory/XtaGetMessageRequestTestFactory.java

@@ -5,7 +5,7 @@ import static de.ozgcloud.xta.test.app.factory.XtaMessageMetaDataTestFactory.*;
 import de.ozgcloud.xta.test.app.model.XtaGetMessageRequest;
 
 public class XtaGetMessageRequestTestFactory {
-	public static String VALID_MESSAGE_ID = "urn:de:xta:messageid:application:000ca2fe-f4e1-45c2-8233-3a0eb760bd16";
+	public static final String VALID_MESSAGE_ID = "urn:de:xta:messageid:application:000ca2fe-f4e1-45c2-8233-3a0eb760bd16";
 
 	public static XtaGetMessageRequest.XtaGetMessageRequestBuilder createBuilder() {
 		return XtaGetMessageRequest.builder()

src/test/java/de/ozgcloud/xta/test/app/service/XtaMessageServiceTest.java

@@ -63,8 +63,8 @@ public class XtaMessageServiceTest {
 	@Nested
 	class TestGetStatusList {
 
-		private final int MAX_LIST_ITEMS = 50;
-		private final int MESSAGE_COUNT = 2;
+		private static final int MAX_LIST_ITEMS = 50;
+		private static final int MESSAGE_COUNT = 2;
 
 		private final XtaMessageMetaDataListingRequest messageMetaDataListingRequest = XtaMessageMetaDataListingRequest.builder()
 				.clientIdentifier(READER_IDENTIFIER)