// ----< posts checkout request to the server >--------------------
        private void Download(RepoFile repoFile)
        {
            RepoClientState state = (RepoClientState)this.DataContext;

            state.ServerCommService.Requests.PostCheckOut(
                repoFile.PackageName,
                repoFile.Namespace,
                repoFile.Filename,
                repoFile.Version,
                state.CheckOutProps.DependentsAreRequired,
                state.ServerConnProps.UserId,
                (CheckOutResponse response) =>
            {
                RepoFile.copyToDest(repoFile, state.CheckOutProps.CheckoutFolder);
                string message = $"Succesfully downloaded file '{repoFile.Filename}' " +
                                 $"to {state.CheckOutProps.CheckoutFolder}";
                MessageBox.Show(message, "Check-Out");
            },
                true);
        }