@Override
  public void appendData(Key key, @NotNull AppendablePersistentMap.ValueDataAppender appender) throws IOException {
    if (myIsReadOnly) throw new IncorrectOperationException();
    if (myWal != null) {
      myWal.appendData(key, appender);
    }

    getWriteLock().lock();
    try {
      doAppendData(key, appender);
    }
    catch (ClosedStorageException e) {
      throw e;
    }
    catch (IOException ex) {
      markCorrupted();
      throw ex;
    }
    finally {
      getWriteLock().unlock();
    }
  }
@Override
  public void appendData(Key key, @NotNull AppendablePersistentMap.ValueDataAppender appender)