代码
http_client: httpx.AsyncClient
# ...

# 发起上游请求
try:
    resp = await http_client.request(
        method=request.method,
        url=target_url,
        headers=forward_headers,
        content=body,
    )
except httpx.RequestError as e:
    return Response(content=f"Upstream request failed: {e}", status_code=502)

async def iter_response():
    async for chunk in resp.aiter_bytes():
        yi...