private void buttonOpenFile_Click(object sender, EventArgs e)
        {
            var openFile = new OpenFileDialog
            {
                ShowReadOnly       = true,
                AddExtension       = true,
                AutoUpgradeEnabled = true,
                Filter             = @"servers.json|servers.json"
            };

            if (openFile.ShowDialog() != DialogResult.OK)
            {
                return;
            }
            var f = File.ReadAllText(openFile.FileName);

            ;
            var cfg = VersionedData.Load(f);

            Text = $"Serverrs.json Editor [Loaded, Api ver. {cfg.Api}]";
            switch (cfg.Api)
            {
            case VersionedServers.ApiVersion:
            {
                var versionedServers = VersionedServers.Load(f);
                ShowEditor_1(versionedServers);
                break;
            }
            }
        }
        private void ShowEditor_1(VersionedServers load)
        {
            _model1            = load;
            _loadedFromFile    = true;
            _createdFromButton = false;
            SetControlsEnabled(true);

            //
            AddOwnServer    = AddOwnServer_1;
            EditOwnServer   = EditOwnServer_1;
            DeleteOwnServer = DeleteOwnServer_1;
            UpdateBindings  = UpdateBindings_1;

            UpdateBindings();
        }