public static ClickHouseEnumValue ofNull(ClickHouseValue ref, Class<? extends Enum> clazz) {
        return ref instanceof ClickHouseEnumValue ? ((ClickHouseEnumValue) ref).set(true, 0)
                : new ClickHouseEnumValue(ClickHouseEnum.of(clazz), true, 0);
    }
Update given value to null or create a new instance if {@code ref} is null.

@param ref   object to update, could be null
@param clazz enum class
@return same object as {@code ref} or a new instance if it's null
clickhouse-data/src/main/java/com/clickhouse/data/value/ClickHouseEnumValue.java