public static ClickHouseEnumValue ofNull(ClickHouseEnum type) {
        return ofNull(null, type);
    }
Create a new instance representing null value.

@param type enum type, null is same as {@link ClickHouseEnum#EMPTY}
@return new instance representing null value
clickhouse-data/src/main/java/com/clickhouse/data/value/ClickHouseEnumValue.java