+1, let`s make !
For the upcoming release 1.36, the default Guava version (and the
version we compile with) will change from 19.0 to the latest,
32.1.3-jre [1]. (We were on 19.0 because Druid needed to use 19.0, and
due to some API changes in Guava, code compiled on 20 or higher cannot
be run on 19.0.)
As before, we will support (and test) a wide range of Guava versions.
But what should be the minimum supported version? I vote for 21.0 [2]
because that was the release where Guava introduced support for JDK 8
features - streams, Supplier. We will be able to remove '::get' from a
few places, and stop using the Util.toImmutableList() collector.
I don't feel strongly about this, but if literally no one needs Guava
19 or 20 anymore let's make the break.
Julian
[1] https://issues.apache.org/jira/browse/CALCITE-5763
[2] https://github.com/google/guava/wiki/Release21
