from commits
  8583da1e
    "java: remove unused fields"
  68cd011c
    "java: reduce scope, make some methods private"
  da677dfd
    "java: reduce scope, make fields private"
  e701b3f7
    "java: reduce scope, make constants private"

Change-Id: I7fe0381c0e17b41bad2e4256c5511fe1f7863498