EmptySearchLogEvent emptyEvent = new EmptySearchLogEvent();
        assertEquals("", emptyEvent.getEventType());
    }

    // Test multiple implementations
    @Test
    public void test_multipleImplementations() {
        // Create different implementations
        SearchLogEvent event1 = new TestSearchLogEvent("id1", 1L, "type1");
        SearchLogEvent event2 = new NullSearchLogEvent();