如何通过crul库和R语结合采集京东图片

```rust
extern crate crul;
extern crate r;

use crul::*;
use r::*;

fn main() {
    // 设置用户代理
    let user_agent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/58.0.3029.110 Safari/537.36".to_string();
    let mut client = Client::new().set_user_agent(user_agent);

    // 获取代理
    let proxy_str = get_proxy();
    let proxy = Proxy::http(proxy_str).unwrap();
    client.set_proxy(proxy);

    // 下载图像
    let image_url = "https://www.jd.com/images/logo.png";
    let mut response = client.get(image_url).send().unwrap();
    let mut image_data = Vec::new();
    response.read_to_end(&mut image_data).unwrap();

    // 保存图像
    let output_path = "./jd_logo.png";
    let mut output = std::fs::File::create(output_path).unwrap();
    output.write_all(&image_data).unwrap();
}

fn get_proxy() -> String {
    // 使用R语言获取代理
    let r = R::<String>::new();
    let proxy_str = r.eval("get_proxy()").unwrap();
    proxy_str
}
```