Apache Druid can store null value for number

I write spec to collect data from kafka. But I know that Druid will auto convert null value of type double, long to 0.0 and 0. ' But I want to store null value instead of 0. So what should I do when set type for each dimension column.

This is a companion discussion topic for the original entry at https://stackoverflow.com/questions/71480544/apache-druid-can-store-null-value-for-number