code: public String getAttribute(
            String rawName, org.w3c.dom.Node sourceNode, TransformerImpl transformer)
              throws TransformerException
    {
  
      AVT avt = getLiteralResultAttribute(rawName);
  
      if ((null != avt) && avt.getRawName().equals(rawName))
      {
        XPathContext xctxt = transformer.getXPathContext();
  
        return avt.evaluate(xctxt, 
              xctxt.getDTMHandleFromNode(sourceNode), 
              this);
      }
  
      return null;
    }
docs: Return the value of the attribute interpreted as an Attribute
  Value Template (in other words, you can use curly expressions
  such as href="http://{website}".
  
  @param rawName Raw name of the attribute to get
  @param sourceNode non-null reference to the <a href="http://www.w3.org/TR/xslt#dt-current-node">current source node</a>.
  @param transformer non-null reference to the the current transform-time state.
  
  @return the value of the attribute
  
  @throws TransformerException