code: public String read() throws IOException {
      CurrentInProgressMetadataWritable cip = localWritable.get();
      if (readAndUpdateVersion(cip)) {
        return cip.getPath();
      } else {
        if (LOG.isDebugEnabled()) {
          LOG.debug(fullyQualifiedZNode + " is currently clear.");
        }
      }
      return null;
    }
docs: Read the full path to the ZNode holding the metadata for the ledger
  containing the current in-progress edit log segment or null if no segment
  is currently in-progress
  @return Full path to the ledger's metadata ZNode or null if no
  segment is in progress
  @throws IOException If there is an error talking to ZooKeeper