code: protected void putNullItem(NullItemData item)
     {
        boolean inTransaction = cache.isTransactionActive();
        try
        {
           if (!inTransaction)
           {
              cache.beginTransaction();
           }
           cache.setLocal(true);
  
           if (!item.getIdentifier().equals(NullItemData.NULL_ID))
           {
              cache.putIfAbsent(new CacheId(getOwnerId(), item.getIdentifier()), item);
           }
           else if (item.getName() != null && item.getParentIdentifier() != null)
           {
              cache.putIfAbsent(
                 new CacheQPath(getOwnerId(), item.getParentIdentifier(), item.getName(), ItemType.getItemType(item)),
                 NullItemData.NULL_ID);
           }
        }
        finally
        {
           cache.setLocal(false);
           if (!inTransaction)
           {
              dedicatedTxCommit();
           }
        }
     }
docs: Internal put NullNode.
  
  @param item, NullItemData, new data to put in the cache