Merge branch 'stable-2.13'

* stable-2.13:
  Use path.toFile().exists() instead of Files.exists(path)
  Fix possible NPE flagged by SonarQube

Change-Id: I34a90f9f26b80a884e393f8c47e94bb9dec70b5c
tree: f285a72daa1c9daf40987c78ff0c5f25b5fdc7c9
  1. .buckconfig
  2. .gitignore
  3. .mailmap
  4. BUCK
  5. lib/
  6. src/