public class LadderRepository : MonoBehaviour {

        private string uri = "my uri";

        private readonly IList<RequestHelper> requests = new List<RequestHelper>();

        public IPromise<LadderResponse> FetchLadder() {
            var requestHelper = ComposeRequest(ladder);
            return RestClient.Get<LadderResponse>(requestHelper);
        }

        private RequestHelper ComposeRequest(string url) {
            var requestHelper = new RequestHelper {
                Uri = url,
                Timeout = 10
            };
            requests.Add(requestHelper);
            return requestHelper;
        }

        private void OnDestroy() {
            foreach (var requestHelper in requests) {
                requestHelper.Abort();
            }

            requests.Clear();
        }

    }

ArgumentNullException: Value cannot be null.
Parameter name: _unity_self
Proyecto26.RequestHelper.Abort () (at Assets/RestClient/Packages/Proyecto26.RestClient/Helpers/RequestHelperExtension.cs:129)
Script.LadderRepository.OnDestroy () (at Assets/Script/Ladder/LadderRepository.cs:30)