Saving Grid(Dev Express) Layout with MVVM(code from DevExpress support)

<Window x:Class="WPFGridTest.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:dxg="http://schemas.devexpress.com/winfx/2008/xaml/grid"
        xmlns:dxgt="http://schemas.devexpress.com/winfx/2008/xaml/grid/themekeys"
        xmlns:dxe="http://schemas.devexpress.com/winfx/2008/xaml/editors"
        xmlns:dx="http://schemas.devexpress.com/winfx/2008/xaml/core"
        xmlns:dxb="http://schemas.devexpress.com/winfx/2008/xaml/bars"
        xmlns:i="http://schemas.microsoft.com/expression/2010/interactivity"
        xmlns:dxlc="http://schemas.devexpress.com/winfx/2008/xaml/layoutcontrol"
        xmlns:local="clr-namespace:WPFGridTest"
        Title="MainWindow" Height="350" Width="525">
    <Window.DataContext>
        <local:VM/>
    </Window.DataContext>
    <Window.Resources>
        <local:SaveRestoreCommands x:Key="saveRestoreLayoutCommands" Path="1.xml"/>
    </Window.Resources>
    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <StackPanel Orientation="Horizontal">
            <Button Content="Save" Command="{Binding Path=SaveLayoutCommand, Source={StaticResource saveRestoreLayoutCommands}}" CommandParameter="{Binding ElementName= g}"/>
            <Button Content="Restore" Command="{Binding Path=RestoreLayoutCommand, Source={StaticResource saveRestoreLayoutCommands}}" CommandParameter="{Binding ElementName=g}"/>
        </StackPanel>
        <dxg:GridControl x:Name="g" Grid.Row="1" ItemsSource="{Binding Source}">
            <dxg:GridControl.View>
                <dxg:TableView x:Name="v"/>
            </dxg:GridControl.View>
            <dxg:GridControl.Columns>
                <dxg:GridColumn x:Name="c1" FieldName="ID"/>
                <dxg:GridColumn x:Name="c2" FieldName="Value"/>
            </dxg:GridControl.Columns>
        </dxg:GridControl>
    </Grid>
</Window>

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Windows;
using System.Windows.Controls;
using System.Windows.Data;
using System.Windows.Documents;
using System.Windows.Input;
using System.Windows.Media;
using System.Windows.Media.Imaging;
using System.Windows.Navigation;
using System.Windows.Shapes;
using DevExpress.Xpf.Grid;
using DevExpress.Xpf.Core.Native;
using DevExpress.Xpf.Bars;
using System.ComponentModel;
using System.Windows.Interactivity;
using DevExpress.Xpf.Core;
using System.ComponentModel.DataAnnotations;
using System.Data;
using System.Collections.ObjectModel;
using DevExpress.Xpf.Editors;
using DevExpress.Data;
using DevExpress.Xpf.Editors.Settings;
using DevExpress.Xpf.Core.Commands;
using System.IO;

namespace WPFGridTest {
    /// <summary>
    /// Interaction logic for MainWindow.xaml
    /// </summary>
    public partial class MainWindow : Window {
        public MainWindow() {
            InitializeComponent();
        }
    }

    public class VM {
        public TestDataList Source { get; set; }
        public VM() {
            Source = TestDataList.Create();
        }
    }
    public class TestDataList : ObservableCollection<TestDataItem> {
        public static TestDataList Create() {
            TestDataList res = new TestDataList();
            TestDataItem item = new TestDataItem();
            item.ID = 0;
            item.Value = "A";
            res.Add(item);
            item = new TestDataItem();
            item.ID = 1;
            item.Value = "b";

            res.Add(item);
            item = new TestDataItem();
            item.ID = 2;
            item.Value = "C";
            res.Add(item);

            item = new TestDataItem();
            item.ID = 3;
            item.Value = "C";
            res.Add(item);
            return res;
        }
    }
    public class TestDataItem {
        public int ID { get; set; }
        public string Value { get; set; }
    }

    public class SaveRestoreLayoutCommandBase : ICommand {
        internal string Path { get; set; }
        public virtual bool CanExecute(object parameter) {
            if (string.IsNullOrEmpty(Path)) return false;
            return true;
        }
        public event EventHandler CanExecuteChanged;
        public virtual void Execute(object parameter) {
            if (!(parameter is GridControl)) throw new Exception();
        }
        internal void RaiseCanExecuteChanged() {
            if (CanExecuteChanged != null) CanExecuteChanged(this, EventArgs.Empty);
        }
    }
    public class SaveLayoutCommand : SaveRestoreLayoutCommandBase {
        public event EventHandler Executed;
        public override void Execute(object parameter) {
            base.Execute(parameter);
            ((GridControl)parameter).SaveLayoutToXml(Path);
            if (Executed != null) Executed(this, EventArgs.Empty);
        }
    }
    public class RestoreLayoutCommand : SaveRestoreLayoutCommandBase {
        public override bool CanExecute(object parameter) {
            if (!base.CanExecute(parameter) || !File.Exists(Path))
                return false;
            return true;
        }
        public override void Execute(object parameter) {
            base.Execute(parameter);
            ((GridControl)parameter).RestoreLayoutFromXml(Path);
        }
    }
    public class SaveRestoreCommands {
        string path;
        public string Path { get { return path; }
            set {
                path = value;
                SaveLayoutCommand.Path = path;
                RestoreLayoutCommand.Path = path;
            }
        }
        public SaveLayoutCommand SaveLayoutCommand { get; private set; }
        public RestoreLayoutCommand RestoreLayoutCommand { get; private set; }
        public SaveRestoreCommands() {
            SaveLayoutCommand = new SaveLayoutCommand() { Path = this.Path };
            RestoreLayoutCommand = new RestoreLayoutCommand() { Path = this.Path };
            SaveLayoutCommand.Executed +=new EventHandler(SaveLayoutCommand_Executed);
        }
        void SaveLayoutCommand_Executed(object sender, EventArgs e) {
            if (RestoreLayoutCommand != null) RestoreLayoutCommand.RaiseCanExecuteChanged();
        }
    }
}