private void Open()
        {
            var options = new FileDialogOptions()
            {
                Filter = FileFilter
            };

            var result = _fileDialogService.ShowOpenFileDialog(options);

            if (result != null)
            {
                var metadata = HostPersistor.LoadFromFile(result.FileName);

                Filename = result.FileName;

                Program = new ProgramViewModel(metadata.Functions);
            }
        }
        private void SaveInner()
        {
            var metadata = GetMetadata();

            HostPersistor.SaveToFile(Filename, metadata);
        }