Function async_google_apis_common::do_download

pub async fn do_download<'a, Req: Serialize + Debug, Resp: DeserializeOwned + Debug, '_>(
    cl: &'a TlsClient, 
    path: &'_ str, 
    headers: Vec<(HeaderName, String)>, 
    http_method: String, 
    rq: Option<&'a Req>
) -> Result<Download<'a, Req, Resp>>