Value key = new Value(CollectionStore.FREE_COLLECTION_ID_KEY);
Value key = new CollectionStore.CollectionKey(CollectionStore.FREE_COLLECTION_ID_KEY);
    protected void freeCollectionId(Txn transaction, short id) throws PermissionDeniedException {               Lock lock = collectionsDb.getLock();        try {            lock.acquire(Lock.WRITE_LOCK);            Value key = new Value(CollectionStore.FREE_COLLECTION_ID_KEY);            Value value = collectionsDb.get(key);            if (value != null) {                byte[] data = value.getData();                byte[] ndata = new byte[data.length + 2];                System.arraycopy(data, 0, ndata, 2, data.length);                ByteConversion.shortToByte(id, ndata, 0);                collectionsDb.put(transaction, key, ndata, true);            } else {                byte[] data = new byte[2];                ByteConversion.shortToByte(id, data, 0);                collectionsDb.put(transaction, key, data, true);            }        } catch (LockException e) {            LOG.warn("Failed to acquire lock on " + collectionsDb.getFile().getName(), e);            //TODO : rethrow ? -pb        } catch (ReadOnlyException e) {            throw new PermissionDeniedException(DATABASE_IS_READ_ONLY);        } finally {            lock.release();        }    }