Make scene nodes internal.

src/Avalonia.Visuals/Rendering/SceneGraph/BrushDrawOperation.cs

@@ -6,7 +6,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public abstract class BrushDrawOperation : IDrawOperation
+    internal abstract class BrushDrawOperation : IDrawOperation
     {
         public abstract Rect Bounds { get; }
         public abstract bool HitTest(Point p);

src/Avalonia.Visuals/Rendering/SceneGraph/GeometryNode.cs

@@ -9,7 +9,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class GeometryNode : BrushDrawOperation
+    internal class GeometryNode : BrushDrawOperation
     {
         public GeometryNode(
             Matrix transform,

src/Avalonia.Visuals/Rendering/SceneGraph/ImageNode.cs

@@ -9,7 +9,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class ImageNode : IDrawOperation
+    internal class ImageNode : IDrawOperation
     {
         public ImageNode(Matrix transform, IBitmapImpl source, double opacity, Rect sourceRect, Rect destRect)
         {

src/Avalonia.Visuals/Rendering/SceneGraph/LineNode.cs

@@ -8,7 +8,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class LineNode : BrushDrawOperation
+    internal class LineNode : BrushDrawOperation
     {
         public LineNode(Matrix transform, Pen pen, Point p1, Point p2)
         {

src/Avalonia.Visuals/Rendering/SceneGraph/RectangleNode.cs

@@ -8,7 +8,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class RectangleNode : BrushDrawOperation
+    internal class RectangleNode : BrushDrawOperation
     {
         public RectangleNode(
             Matrix transform,

src/Avalonia.Visuals/Rendering/SceneGraph/TextNode.cs

@@ -9,7 +9,7 @@ using Avalonia.VisualTree;
 
 namespace Avalonia.Rendering.SceneGraph
 {
-    public class TextNode : IDrawOperation
+    internal class TextNode : IDrawOperation
     {
         public TextNode(Matrix transform, IBrush foreground, Point origin, IFormattedTextImpl text)
         {