@Override
  public void close() {
    if (closed.compareAndSet(false, true)) {
      txOptions.close();
      options.close();
      tryDeleteOptions.close();
      columnHandlesBySegmentIdentifier.values().stream()
          .map(RocksDbSegmentIdentifier::get)
          .forEach(ColumnFamilyHandle::close);
      getDB().close();
    }
  }
Safe method to map segment identifier to column handle.

@param segment segment identifier
@return column handle
plugins/rocksdb/src/main/java/org/hyperledger/besu/plugin/services/storage/rocksdb/segmented/RocksDBColumnarKeyValueStorage.java