Downloading a file and showing progress via curl.

[BoQsc]

Hello everyone,
I found this snippet on 
https://dlang.org/phobos/std_net_curl.html#.HTTP

> import std.net.curl : HTTP;
> import std.stdio : writeln;
> 
> void main()
> {
>     auto http = HTTP();
>     // Track progress
>     http.method = HTTP.Method.get;
>     http.url = 
> "https://upload.wikimedia.org/wikipedia/commons/5/53/Wikipedia-logo-en-big.png";
>     http.onReceive = (ubyte[] data) { return data.length; };
>     http.onProgress = (size_t dltotal, size_t dlnow, size_t 
> ultotal, size_t ulnow) {
>         writeln("Progress ", dltotal, ", ", dlnow, ", ", 
> ultotal, ", ", ulnow);
>         return 0;
>     };
>     http.perform();
> }

This snippet is showing Download Progress in bytes, but I'm 
unsure how to save the
downloaded file into filesystem after download is completed.