code: protected void appendCssNode(HttpServletRequest request, Document document, DocumentFragment head, Css css, String relativeRoot) {
          final String stylePath = getElementPath(request, css, relativeRoot);
  
          if (resourcesDao.isConditional(css)) {
              Comment c = document.createComment("");
              c.appendData(OPEN_COND_COMMENT_PRE);
              c.appendData(css.getConditional());
              c.appendData(OPEN_COND_COMMENT_POST);
              c.appendData(OPEN_STYLE);
              c.appendData(stylePath);
              if (StringUtils.isNotBlank(css.getMedia())) {
                  c.appendData("\" media=\"");
                  c.appendData(css.getMedia());
              }
              c.appendData(CLOSE_STYLE);
              c.appendData(CLOSE_COND_COMMENT);
              head.appendChild(c);
          }
          else {
              Element element = document.createElement(LINK);
              element.setAttribute(REL, "stylesheet");
              element.setAttribute(TYPE, "text/css");
              element.setAttribute(HREF, stylePath);
              if (StringUtils.isNotBlank(css.getMedia())) {
                  element.setAttribute(MEDIA, css.getMedia());
              }
              head.appendChild(element);
          }
      }
docs: Convert the {@link Css} argument to an HTML link tag and append it
  to the {@link DocumentFragment}.