public static String asIncludeContent(JetPageContext ctx, String relativeName, Map<String, Object> parameters) {
if (relativeName == null || relativeName.length() == 0) {
throw new IllegalArgumentException("argument relativeName is null or empty.");
}
String file = ctx.getAbsolutionName(relativeName);
JetTemplate template = ctx.getEngine().getTemplate(file);
JetContext context = new JetContext(ctx.getContext(), parameters);
UnsafeCharArrayWriter os = new UnsafeCharArrayWriter();
template.render(context, os);
return os.toString();
}