private HttpWebRequest CreateRequest(string serviceUrl, ICredentials credentials)
{
var trailing = serviceUrl.Contains("?") ? "&" : "?";
var requestUrl = $"{serviceUrl}/legend{trailing}f=json";
_webRequest = (HttpWebRequest)WebRequest.Create(requestUrl);
if (credentials == null)
_webRequest.UseDefaultCredentials = true;
else
_webRequest.Credentials = credentials;
return _webRequest;
}