Along the same vein as
HADOOP-11286, there are now several remaining usages of guava APIs that are now incompatible with a more recent version (e.g. 16).
This JIRA proposes eliminating those usages. With this, the hadoop code base should run/compile cleanly even if guava 16 is used for example.
This JIRA doesn't propose upgrading the guava dependency version however (just making the codebase compatible with guava 16+).