How to use the httpstan.models function in httpstan

async def go():
        io = ConsoleIO()
        io.error("Building...")
        async with stan.common.httpstan_server() as (host, port):
            # Check to see if model is in cache.
            model_name = httpstan.models.calculate_model_name(program_code)
            path, payload = f"/v1/{model_name}/params", {"data": data}
            async with aiohttp.request("POST", f"http://{host}:{port}{path}", json=payload) as resp:
                model_in_cache = resp.status != 404
            io.error_line(" Found model in cache." if model_in_cache else " This may take some time.")
            # Note: during compilation `httpstan` redirects stderr to /dev/null, making `print` impossible.
            path, payload = "/v1/models", {"program_code": program_code}
            async with aiohttp.request("POST", f"http://{host}:{port}{path}", json=payload) as resp:
                if resp.status != 201:
                    raise RuntimeError((await resp.json())["message"])
                assert model_name == (await resp.json())["name"]

            path, payload = f"/v1/{model_name}/params", {"data": data}
            async with aiohttp.request("POST", f"http://{host}:{port}{path}", json=payload) as resp:
                if resp.status != 200:
                    raise RuntimeError((await resp.json())["message"])
                params_list = (await resp.json())["params"]