System.Windows.DependencyProperty.OverrideMetadata C# (CSharp) Method

        public void OverrideMetadata(Type forType, PropertyMetadata typeMetadata)
        {
            if (forType == null)
                throw new ArgumentNullException ("forType");
            if (typeMetadata == null)
                throw new ArgumentNullException ("typeMetadata");

            if (ReadOnly)
                throw new InvalidOperationException (String.Format ("Cannot override metadata on readonly property '{0}' without using a DependencyPropertyKey", Name));

            typeMetadata.DoMerge (DefaultMetadata, this, forType);
            metadataByType.Add (forType, typeMetadata);
        }

 static MainWindow()
 {
     FrameworkPropertyMetadata metadata = new FrameworkPropertyMetadata();
     metadata.Inherits = true;
     SpaceProperty = SpaceButton.SpaceProperty.AddOwner(typeof(MainWindow));
     SpaceProperty.OverrideMetadata(typeof(Window), metadata);
 }