Java SDK: How to pass null value to a parameter?

[oleg68]

I have a yql query block:

declare $id as uint64;
declare $last_date as datetime;
replace into table (id, last_date)
  values ($id, $last_date)

For passing the psarameters to the query block I use

Params.of(
  "$id", PrimitiveValue.uint64(rec.getId()),
  "$last_date", PrimitiveValue.datetime(rec.getLastDate().getTime())
);

This passes a not-null value to $last_date. But what should I use for passing null to $last_date?

[oleg68]

com.yandex.ydb.table.values.OptionalType.of(PrimitiveType.datetime()).emptyValue();