test/template/test.tpl

<!doctype html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport"
        content="width=device-width, user-scalable=no, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <title>{{ title }}</title>
</head>
<body>
  {% block main %}
    test.tpl content
  {% endblock %}

  {% block script %}
    default script
  {% endblock %}
</body>
</html>