public T SendGet <T>(string relativeUrl)
            where T : new()
        {
            Request.Resource = relativeUrl;
            IRestResponse <T> response = client.Get <T>(Request);

            CheckResponseCode?.Invoke(response);

            return(response.Data);
        }
        public T SendPostAsJson <T>(object body, string relativeUrl)
        {
            Request.AddJsonBody(body);
            Request.Resource = relativeUrl;
            Request.Method   = Method.POST;

            IRestResponse <T> response = client.ExecuteAsync <T>(Request).GetAwaiter().GetResult();

            CheckResponseCode?.Invoke(response);

            return(response.Data);
        }