docs: def render_impl(self, template, context, **kwargs):
          """
          Render given template file and return the result.
  
          :param template: Template file path
          :param context: A dict or dict-like object to instantiate given
              template file
          :param kwargs: Keyword arguments such as:
              - at_paths: Template search paths but it is not actually processed
                in this module (TODO)
              - at_encoding: Template encoding but it is not actually prcoessed
                in this module (TODO)
              - Other keyword arguments passed to the template engine to render
                templates with specific features enabled.
  
          :return: Rendered string
          """
          if "source" in kwargs:
              kwargs["source"] = None
  
          kwargs["file"] = template
  
          return self.__render(context, **kwargs)