How to use the fdk.runner.handle_request function in fdk

async def pure_handler(request):
        log.log("in pure_handler")
        data = None
        if request.has_body:
            log.log("has body: {}".format(request.has_body))
            log.log("request comes with data")
            data = await request.content.read()
        response = await runner.handle_request(
            handle_func, constants.HTTPSTREAM,
            request=request, data=data)
        log.log("request execution completed")
        headers = response.context().GetResponseHeaders()

        response_content_type = headers.get(
            constants.CONTENT_TYPE, "application/json"
        )
        headers.set(constants.CONTENT_TYPE, response_content_type)
        kwargs = {
            "headers": headers.http_raw()
        }

        sdata = serialize_response_data(
            response.body(), response_content_type)

async def pure_handler(request):
        logger.info("in pure_handler")
        func_response = await runner.handle_request(
            handle_code, constants.HTTPSTREAM,
            headers=dict(request.headers), data=io.BytesIO(request.body))
        logger.info("request execution completed")
        return func_response

async def pure_handler(request):
        from fdk import runner
        logger.info("in pure_handler")
        headers = dict(request.headers)
        log_frame_header(headers)
        func_response = await runner.handle_request(
            handle_code, constants.HTTPSTREAM,
            headers=headers, data=io.BytesIO(request.body))
        logger.info("request execution completed")

        headers = func_response.context().GetResponseHeaders()
        status = func_response.status()
        if status not in constants.FN_ENFORCED_RESPONSE_CODES:
            status = constants.FN_DEFAULT_RESPONSE_CODE

        return response.HTTPResponse(
            headers=headers,
            status=status,
            content_type=headers.get(constants.CONTENT_TYPE),
            body_bytes=func_response.body_bytes(),
        )

async def setup_fn_call_raw(handle_func, content=None, headers=None):

    if headers is None:
        headers = {}

    # don't decap headers, so we can test them
    # (just like they come out of fdk)
    return process_response(runner.handle_request(
        code(handle_func), constants.HTTPSTREAM,
        headers=headers, data=content,
    ))