code: public int doStartTag() throws JspException {
          //log("XML: " + mDocumentURI + " XSL: " + mStylesheetURI);
  
          if (mDocumentURI != null) {
              // If document given, transform and skip body...
              try {
                  transform(getSource(mDocumentURI));
              }
              catch (MalformedURLException murle) {
                  throw new JspException(murle.getMessage(), murle);
              }
              catch (IOException ioe) {
                  throw new JspException(ioe.getMessage(), ioe);
              }
  
              return SKIP_BODY;
          }
  
          // ...else process the body
          return EVAL_BODY_BUFFERED;
      }
docs: doStartTag implementation, that performs XML Transformation on the
  given document, if any.
  If the documentURI attribute is set, then the transformation is
  performed on the document at that location, and
  {@code Tag.SKIP_BODY} is returned.
  Otherwise, this method simply returns
  {@code BodyTag.EVAL_BODY_BUFFERED} and leaves the transformation to
  the doEndTag.
  
  @return {@code Tag.SKIP_BODY} if {@code documentURI} is not
  {@code null}, otherwise
  {@code BodyTag.EVAL_BODY_BUFFERED}.
  
  @todo Is it really a good idea to allow "inline" XML in a JSP?