assertFalse(registration.isExpired(60000));

        // Verify heartbeat was actually updated
        assertTrue(registration.getLastHeartbeat() > initialTime);
    }

    @Test
    void testExpiration() throws InterruptedException {
        // Registration should not be expired initially with long timeout
        assertFalse(registration.isExpired(60000));

        // Wait a bit to ensure some time has passed

        entry.invalidate();

        assertFalse(entry.isComplete());
        assertTrue(entry.hasChanges());
        assertTrue(entry.getChildren().isEmpty());
    }

    @Test
    public void testExpiration() {
        // Set a very short max age
        entry.setMaxAge(100); // 100ms

        assertFalse(entry.isExpired());
        assertFalse(entry.needsRefresh());

        // Wait for expiration

        }
    }

    @Nested
    @DisplayName("Expiration Tests")
    class ExpirationTests {

        @Test
        @DisplayName("Should get and set expiration")
        void testExpiration() {
            Long expiration = 1000L;

            response.setExpiration(expiration);

            assertEquals(expiration, response.getExpiration());
        }

        @Test

        }
    }

    @Nested
    @DisplayName("Expiration Tests")
    class ExpirationTests {

        @Test
        @DisplayName("Should manage expiration time")
        void testExpiration() {
            assertNull(echoResponse.getExpiration());

            Long expiration = System.currentTimeMillis() + 10000L;
            echoResponse.setExpiration(expiration);