private IEnumerator Request(Delegates.AssetServiceCallback requestCallback)
{
pending = true;
NetworkEvent.NetworkRequestStart(this);
webRequest = new UnityWebRequest(url, UnityWebRequest.kHttpVerbGET);
webRequest.downloadHandler = new DownloadHandlerBuffer();
#if UNITY_2017_3_OR_NEWER
yield return(webRequest.SendWebRequest());
#else
yield return(webRequest.Send());
#endif
pending = false;
OnRequestCompleted(requestCallback);
}