Нельзя преобразовать тип Google.GData.Client.AtomLink к Google.GData.Client.AtomLink

var docentry := new SpreadsheetEntry;
docentry.Title.Text := filename;
docentry.MediaSource.Name := file_to_up;
docentry.MediaSource.ContentType := 'application/excel';
var entrylink := new AtomLink('https://spreadsheets.google.com/feeds/upload/create-session/default/private/full');
entrylink.Rel := ResumableUpload.ResumableUploader.CreateMediaRelation;
docentry.Links.Add(up_url); //Вот тут и возникает ошибка

procedure UploadToGoogle;
begin
var fileup: String := 'C:\Documents\Upload.xlsx';
var filename: String := System.IO.Path.GetFileNameWithoutExtension(fileup);
var authgoogle := new OAuth2Parameters;
authg.ClientId := '****';
authg.ClientSecret := '****';
authg.RedirectUri := 'urn:ietf:wg:oauth:2.0:oob';
authg.Scope := 'https://spreadsheets.google.com/feeds/';
var aurl: String := OAuthUtil.CreateOAuth2AuthorizationUrl(authg);
//Access Code пока не рабочий
authg.AccessCode := 'access';
OAuthUtil.GetAccessToken(authg);
var a := new OAuth2Authenticator('App',authg);
var arf := new GOAuth2RequestFactory('apps','App',authg);
var s := new SpreadsheetsService('App');
docentry.Title.Text := filename;
docentry.MediaSource.Name := fileup;
docentry.MediaSource.ContentType := 'application/excel';
var entrylink := new AtomLink('https://spreadsheets.google.com/feeds/upload/create-session/default/private/full');
entrylink.Rel := ResumableUpload.ResumableUploader.CreateMediaRelation;
docentry.Links.Add(entrylink);
docentry.Service := s;
var u := new ResumableUpload.ResumableUploader;
u.InsertAsync(a,docentry,new Object); 
end;

docentry.Links.Add(new AtomLink(entrylink.ToString,entrylink.Rel));