postcard.setDataCrawlStartTime(getValueFromMap(dataMap, "dataCrawlStartTime", StringUtil.EMPTY));
                    postcard.setDataIndexSize(getValueFromMap(dataMap, "dataIndexSize", "0"));
                    postcard.setDataIndexExecTime(getValueFromMap(dataMap, "dataIndexExecTime", "0"));

            fail("Should not throw exception with empty map: " + e.getMessage());
        }
    }

    // Test getValueFromMap private method via reflection
    @Test
    public void test_getValueFromMap() throws Exception {
        Method method = Crawler.class.getDeclaredMethod("getValueFromMap", Map.class, String.class, String.class);
        method.setAccessible(true);

        Map<String, String> dataMap = new HashMap<>();