private EditSession GetEditSession(string fileId)
        {
            var sessionId           = /*Context.Session.GetString("SessionID");
                                       * if (string.IsNullOrEmpty(sessionId))
                                       * {
                                       * sessionId = Guid.NewGuid().ToString();
                                       * Context.Session.SetString("SessionID", sessionId);
                                       * }
                                       * sessionId += "|" +*/fileId;
            EditSession editSession = SessionManager.Current.GetSession(sessionId);

            if (editSession == null)
            {
                IWopiFile file = FileProvider.GetWopiFile(fileId);

                //TODO: remove hardcoded action 'Edit'
                if (WopiDiscoverer.RequiresCobalt(file.Extension, WopiActionEnum.Edit))
                {
                    editSession = new CobaltSession(file, sessionId);
                }
                else
                {
                    editSession = new FileSession(file, sessionId);
                }
                SessionManager.Current.AddSession(editSession);
            }

            return(editSession);
        }