The question about the Apache Calcite 2.0's progress

[LakeShen]

Hi community,

Now I am reading the Calcite source code,and I find that there are a lot of
code comments  which are marked to be removed before 2.0.What is the status
of Apache Calcite 2.0？Where can I see Apache Calcite 2.0 progress?

Best,
LakeShen.