writeNamespaceImpl(prefix, namespaceURI);
  public void writeNamespace(String prefix, String namespaceURI)    throws XMLStreamException  {    if (!inStartElement)      throw new IllegalStateException();    try      {        if (prefix == null)          prefix = XMLConstants.DEFAULT_NS_PREFIX;        setPrefix(prefix, namespaceURI);                writer.write(' ');        writer.write("xmlns");        if (!XMLConstants.DEFAULT_NS_PREFIX.equals(prefix))          {            writer.write(':');            writer.write(prefix);          }        writer.write('=');        writer.write('"');        writer.write(namespaceURI);        writer.write('"');      }    catch (IOException e)      {        XMLStreamException e2 = new XMLStreamException(e);        e2.initCause(e);        throw e2;      }  }