@VisibleForTesting
    public static Map<String, ColumnStats> convertToColumnStatsMap(
            Map<String, CatalogColumnStatisticsDataBase> columnStatisticsData) {
        Map<String, ColumnStats> columnStatsMap = new HashMap<>();
        for (Map.Entry<String, CatalogColumnStatisticsDataBase> entry :
                columnStatisticsData.entrySet()) {
            if (entry.getValue() != null) {
                ColumnStats columnStats = convertToColumnStats(entry.getValue());
                columnStatsMap.put(entry.getKey(), columnStats);
            }
        }
        return columnStatsMap;
    }
@Test
    void testConvertToColumnStatsMapWithNullColumnStatisticsData() {
        Map<String, CatalogColumnStatisticsDataBase> columnStatisticsDataBaseMap = new HashMap<>();
        columnStatisticsDataBaseMap.put(
                "first", new CatalogColumnStatisticsDataString(10L, 5.2, 3L, 100L));
        columnStatisticsDataBaseMap.put("second", null);
        Map<String, ColumnStats> columnStatsMap =
                CatalogTableStatisticsConverter.convertToColumnStatsMap(
                        columnStatisticsDataBaseMap);
        assertThat(columnStatsMap).isNotNull();
        assertThat(columnStatsMap).hasSize(columnStatisticsDataBaseMap.size() - 1);
        assertThat(columnStatsMap).containsKey("first");
        assertThat(columnStatsMap).doesNotContainKey("second");
    }