private List <Membership> ListMembershipByPersonId(string roomId, string personId) { var completion = new ManualResetEvent(false); var response = new SparkApiEventArgs <List <Membership> >(); memberships.ListByPersonId(roomId, personId, rsp => { response = rsp; completion.Set(); }); if (false == completion.WaitOne(30000)) { return(null); } if (response.IsSuccess == true) { return(response.Data); } return(null); }