FileUtils.mkdirs(new File(db.getWorkTree(), "a"));
writeTrashFile("a/c", "Hello world c");
writeTrashFile("b", "Hello world b");
git.add().addFilepattern(".").call();
git.commit().setMessage("add folder a & file b").call();
Ref branch_1 = git.branchCreate().setName("branch_1").call();
git.rm().addFilepattern("a").call();
File fileA = new File(db.getWorkTree(), "a");
writeTrashFile("a", "b");
git.add().addFilepattern("a").call();
git.commit().setMessage("add file a").call();