protected override void Handle()
 {
     if (MessageButtons.No == VsAppShell.Current.ShowMessage(Resources.Warning_DeleteAllVariables, MessageButtons.YesNo))
     {
         return;
     }
     try {
         RSession.ExecuteAsync("rm(list = ls(all = TRUE))").DoNotWait();
     } catch (RException ex) {
         VsAppShell.Current.ShowErrorMessage(
             string.Format(CultureInfo.InvariantCulture, Resources.Error_UnableToDeleteVariable, ex.Message));
     } catch (MessageTransportException) { }
 }
        protected override void Handle()
        {
            var ui = _workflow.Services.UI();

            if (MessageButtons.No == ui.ShowMessage(Resources.Warning_DeleteAllVariables, MessageButtons.YesNo))
            {
                return;
            }
            try {
                RSession.ExecuteAsync("rm(list = ls(all = TRUE))").DoNotWait();
            } catch (RException ex) {
                ui.ShowErrorMessage(Resources.Error_UnableToDeleteVariable.FormatInvariant(ex.Message));
            } catch (ComponentBinaryMissingException ex) {
                ui.ShowErrorMessage(Resources.Error_UnableToDeleteVariable.FormatInvariant(ex.Message));
            } catch (OperationCanceledException) { }
        }