code: @Override
     protected void entering(NodeData node, int level) throws RepositoryException
     {
        try
        {
           writer.writeStartElement(Constants.NS_SV_PREFIX, Constants.SV_NODE, getSvNamespaceUri());
           if (level == 0)
           {
              startPrefixMapping();
           }
  
           writer.writeAttribute(Constants.NS_SV_PREFIX, getSvNamespaceUri(), Constants.SV_NAME, getExportName(node,
              false));
        }
        catch (XMLStreamException e)
        {
           throw new RepositoryException(e);
        }
  
     }
docs: /*
  (non-Javadoc)
  @see
  org.exoplatform.services.jcr.dataflow.ItemDataTraversingVisitor#entering(org.exoplatform.services
  .jcr.datamodel.NodeData, int)