@Override
    protected Class<? extends SubView> header() {
        try {
            if (WebApps.Builder.class.getMethod("build", WebApp.class) != null) {
                return HeaderBlock.class;
            }
        } catch (NoSuchMethodException e) {
            LOG.debug("current hadoop version don't have the method build of Class " + WebApps.class.toString()
                    + ". For More Detail: " + e);
            return org.apache.hadoop.yarn.webapp.view.HeaderBlock.class;
        }
        return null;
    }
Render a page that describes a specific job.
history-server/src/main/java/net/qihoo/hbox/jobhistory/HsJobPage.java