How to write QueryBuilder Query to clean set or list value in Cassandra

Question

Given a table:

CREATE TABLE User (
  id text,
  emails set<text>,
  PRIMARY KEY ((id))
)

How do I write the equivalent of the query below using QueryBuilder?

UPDATE User  SET emails = {} where id='xxx' 

By checking QueryBuilder class I found how to add/remove specific elements, and how to set a non-list, but not how to clear the list without specifying every element.

Answer 1

Setting to null apparently have the exact same result, so:

QueryBuilder.update("User")
 .where(QueryBuilder.eq("id","xxx"))
 .with(QueryBuilder.set("emails",null))

Did the trick.