code: def render_to_string(self, env, **kwargs):
          
          template = None
          template_path = env.get(self.jenv.env_template_dir_key)
  
          if template_path:
              # jinja paths are not os paths, always use '/' as separator
              # https://github.com/pallets/jinja/issues/411
              template_path = template_path + '/' + self.insert_file
  
              try:
                  template = self.jenv.jinja_env.get_template(template_path)
              except TemplateNotFound as te:
                  pass
  
          if not template:
              template = self.jenv.jinja_env.get_template(self.insert_file)
  
          params = env.get(self.jenv.env_template_params_key)
          if params:
              kwargs.update(params)
  
          kwargs['env'] = env
          kwargs['static_prefix'] = env.get('pywb.host_prefix', '') + env.get('pywb.app_prefix', '') + '/static'
  
  
          return template.render(**kwargs)
docs: Render this template.
  
          :param dict env: The WSGI environment associated with the request causing this template to be rendered
          :param any kwargs: The keyword arguments to be supplied to the Jninja template render method
          :return: The rendered template
          :rtype: str