code: public org.w3c.dom.Node readNode()
          throws IOException
      {
          int tag = read();
  
          switch (tag) {
              case 'N':
                  return null;
  
              case 'S':
              case 's':
              case 'X':
              case 'x':
                  _isLastChunk = tag == 'S' || tag == 'X';
                  _chunkLength = (read() << 8) + read();
  
                  throw error("Can't handle string in this context");
  
              default:
                  throw expect("string", tag);
          }
      }
docs: Reads an XML node.
  
  <pre>
  S b16 b8 string value
  </pre>