protected PushOneCommit.Result amendChange(String changeId) throws GitAPIException, IOException {
   Collections.shuffle(RANDOM);
   PushOneCommit push =
       pushFactory.create(
           db,
           admin.getIdent(),
           PushOneCommit.SUBJECT,
           PushOneCommit.FILE_NAME,
           new String(Chars.toArray(RANDOM)),
           changeId);
   return push.to(git, "refs/for/master");
 }
 protected PushOneCommit.Result createChange() throws GitAPIException, IOException {
   PushOneCommit push = pushFactory.create(db, admin.getIdent());
   return push.to(git, "refs/for/master");
 }