code: Source getSourceFromBodyContent() throws JspTagException, SAXException, ParserConfigurationException {
          if (bodyContent == null) {
              throw new JspTagException(Resources.getMessage("TRANSFORM_BODY_IS_NULL"));
          }
          String s = bodyContent.getString();
          if (s == null) {
              throw new JspTagException(Resources.getMessage("TRANSFORM_BODY_CONTENT_IS_NULL"));
          }
          s = s.trim();
          if (s.length() == 0) {
              throw new JspTagException(Resources.getMessage("TRANSFORM_BODY_IS_EMPTY"));
          }
          return XmlUtil.newSAXSource(new StringReader(s), xmlSystemId, entityResolver);
      }
docs: Return the Source for a document specified as body content.
  
  @return the document Source
  @throws JspTagException if there is a problem with the body content