This PR proposes to add null-checking for some parameter arguments in `ZipFileStore`.
------------- Commit messages: - Check null invariants Changes: https://git.openjdk.org/jdk/pull/11926/files Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=11926&range=00 Issue: https://bugs.openjdk.org/browse/JDK-8299864 Stats: 49 lines in 2 files changed: 26 ins; 1 del; 22 mod Patch: https://git.openjdk.org/jdk/pull/11926.diff Fetch: git fetch https://git.openjdk.org/jdk pull/11926/head:pull/11926 PR: https://git.openjdk.org/jdk/pull/11926
