code: private long findMaxTransaction()
        throws IOException {
      for (EditLogFile elf : getLogFiles(0)) {
        if (elf.isInProgress()) {
          maxSeenTransaction = Math.max(elf.getFirstTxId(), maxSeenTransaction);
        }
        maxSeenTransaction = Math.max(elf.getLastTxId(), maxSeenTransaction);
      }
      return maxSeenTransaction;
    }
docs: Find the maximum transaction in the journal.
  This gets stored in a member variable, as corrupt edit logs
  will be moved aside, but we still need to remember their first
  tranaction id in the case that it was the maximum transaction in
  the journal.