diff --git a/src/main/java/java_stream_api/App.java b/src/main/java/java_stream_api/App.java
index bba9a60..a8f4617 100644
--- a/src/main/java/java_stream_api/App.java
+++ b/src/main/java/java_stream_api/App.java
@@ -180,9 +180,7 @@ public static List<User> convertBirthdatesToString(List<User> users) {
 
     // 30. Filter a list of Person objects, keeping only those who live in "City X".
     public static List<Person> filterPersonsByCity(List<Person> persons, String city) {
-        return persons.stream()
-                .filter(p -> city.equals(p.getCity()))
-                .collect(Collectors.toList());
+        return persons.stream().filter(p -> city.equals(p.getCity())).collect(Collectors.toList());
     }
 
     // 31. Reverse the order of elements in a list.
diff --git a/src/test/java/java_stream_api/AppTest.java b/src/test/java/java_stream_api/AppTest.java
index 4e735d1..dc7c75f 100644
--- a/src/test/java/java_stream_api/AppTest.java
+++ b/src/test/java/java_stream_api/AppTest.java
@@ -448,4 +448,10 @@ void testUserNamesSortedByLength() {
         List<String> result = App.userNamesSortedByLength(Arrays.asList(u1, u2, u3));
         assertEquals(Arrays.asList("Eve", "Abi", "Angelina"), result, "Sort by length ascending");
     }
+
+    @Test
+    @DisplayName("Main method runs without throwing exceptions")
+    void testMainRunsWithoutException() {
+        assertDoesNotThrow(() -> App.main(new String[] {}));
+    }
 }