def render(self, resource):
        """
        Render the given resource as a response to this request.

        This implementation only handles a few of the most common behaviors of
        resources.  It can handle a render method that returns a string or
        C{NOT_DONE_YET}.  It doesn't know anything about the semantics of
        request methods (eg HEAD) nor how to set any particular headers.
        Basically, it's largely broken, but sufficient for some tests at least.
        It should B{not} be expanded to do all the same stuff L{Request} does.
        Instead, L{DummyRequest} should be phased out and L{Request} (or some
        other real code factored in a different way) used.
        """
        result = resource.render(self)
        if result is NOT_DONE_YET:
            return
        self.write(result)
        self.finish()

        Render the given resource as a response to this request.

        This implementation only handles a few of the most common behaviors of
        resources.  It can handle a render method that returns a string or
        C{NOT_DONE_YET}.  It doesn't know anything about the semantics of
        request methods (eg HEAD) nor how to set any particular headers.
        Basically, it's largely broken, but sufficient for some tests at least.
        It should B{not} be expanded to do all the same stuff L{Request} does.
        Instead, L{DummyRequest} should be phased out and L{Request} (or some
        other real code factored in a different way) used.
        
stackoverflow/venv/lib/python3.6/site-packages/twisted/web/test/requesthelper.py