assertTrue(result.contains("2021") || result.contains("Jan") || result.contains("1609459200000"));
    }

    // Test appendTimestamp method
    @Test
    public void test_appendTimestamp() {
        StringBuilder buf = new StringBuilder();

        monitorTarget.appendTimestamp(buf);
        String result = buf.toString();

        searchRenderData.setRequestedTime(currentTime);
        assertEquals(currentTime, searchRenderData.getRequestedTime());

        // Test with specific timestamp
        long timestamp = 1609459200000L; // 2021-01-01 00:00:00 UTC
        searchRenderData.setRequestedTime(timestamp);
        assertEquals(timestamp, searchRenderData.getRequestedTime());

        // Test with negative value