Please provide the code changes or file diffs you would like me to summarize.

backend/src/test/java/com/sshmanager/service/SessionTreeLayoutServiceTest.java

@@ -23,6 +23,7 @@ import static org.mockito.Mockito.verify;
 import static org.mockito.Mockito.when;
 
 @ExtendWith(MockitoExtension.class)
+@SuppressWarnings("null")
 class SessionTreeLayoutServiceTest {
 
     @Mock