Minor Description
In https://github.com/apache/spark/pull/2315, I found two cases where @DeveloperAPI and @Experimental annotations didn't prevent false-positive warnings from Mima. To reproduce this problem, run dev/mima as of https://github.com/JoshRosen/spark/commit/ec90e21947b615d4ef94a3a54cfd646924ccaf7c. The spurious warnings are listed at the top of https://gist.github.com/JoshRosen/5d8df835516dc367389d.
