code: public void execute(
            TransformerImpl transformer)
              throws TransformerException
    {
  
      if (transformer.isRecursiveAttrSet(this))
      {
        throw new TransformerException(
          XSLMessages.createMessage(
            XSLTErrorResources.ER_XSLATTRSET_USED_ITSELF,
            new Object[]{ m_qname.getLocalPart() }));  //"xsl:attribute-set '"+m_qname.m_localpart+
      }
  
      transformer.pushElemAttributeSet(this);
      super.execute(transformer);
  
      ElemAttribute attr = (ElemAttribute) getFirstChildElem();
  
      while (null != attr)
      {
        attr.execute(transformer);
  
        attr = (ElemAttribute) attr.getNextSiblingElem();
      }
  
      transformer.popElemAttributeSet();
    }
docs: Apply a set of attributes to the element.
  
  @param transformer non-null reference to the the current transform-time state.
  
  @throws TransformerException