Function upload_test 

pub async fn upload_test(
    client: &Client,
    server: &Server,
    single: bool,
    progress: Arc<SpeedProgress>,
) -> Result<(f64, f64, u64, Vec<f64>), SpeedtestError>

Run upload bandwidth test against the given server.

Returns (avg_speed_bps, peak_speed_bps, total_bytes_uploaded, speed_samples).

Errors

Returns SpeedtestError::NetworkError if all upload streams fail.