public void DelFromWatchers(object nameadded) { JSONRequest jsonrequest = new JSONRequest { urlRequest = $"/rest/api/2/issue/{this.issueKey}/watchers?username={(((RTMobile.User)nameadded).name)}", methodRequest = "DELETE" }; Request requestIssue = new Request(jsonrequest); requestIssue.GetResponses <RootObject>(); if (Additional.Count != 0) { Additional.Remove((RTMobile.User)nameadded); watchers.Remove(new Watchers { name = ((RTMobile.User)nameadded).name, displayName = ((RTMobile.User)nameadded).displayName }); OnPropertyChanged(nameof(Additional)); OnPropertyChanged(nameof(watchers)); } }