# System.Windows.Forms.Design

``` diff
 namespace System.Windows.Forms.Design {
     public class ControlDesigner : ComponentDesigner {
-        protected AccessibleObject accessibilityObj;
+        protected AccessibleObject? accessibilityObj;
-        protected BehaviorService BehaviorService { get; }
+        protected BehaviorService? BehaviorService { get; }
-        protected override InheritanceAttribute InheritanceAttribute { get; }
+        protected override InheritanceAttribute? InheritanceAttribute { get; }
-        protected override IComponent ParentComponent { get; }
+        protected override IComponent? ParentComponent { get; }
-        public virtual ControlDesigner InternalControlDesigner(int internalControlIndex);
+        public virtual ControlDesigner? InternalControlDesigner(int internalControlIndex);
     }
 }
```

