# System.Windows.Forms.Design.Behavior

``` diff
 namespace System.Windows.Forms.Design.Behavior {
     public sealed class Adorner {
-        public BehaviorService BehaviorService { get; set; }
+        public BehaviorService? BehaviorService { get; set; }
     }
     public sealed class BehaviorService : IDisposable {
-        public Behavior CurrentBehavior { get; }
+        public Behavior? CurrentBehavior { get; }
-        public event BehaviorDragDropEventHandler BeginDrag;
+        public event BehaviorDragDropEventHandler? BeginDrag;
-        public event BehaviorDragDropEventHandler EndDrag;
+        public event BehaviorDragDropEventHandler? EndDrag;
-        public event EventHandler Synchronize;
+        public event EventHandler? Synchronize;
-        public Behavior GetNextBehavior(Behavior behavior);
+        public Behavior? GetNextBehavior(Behavior behavior);
-        public Behavior PopBehavior(Behavior behavior);
+        public Behavior? PopBehavior(Behavior behavior);
     }
     public sealed class SnapLine {
-        public SnapLine(SnapLineType type, int offset, string filter);
+        public SnapLine(SnapLineType type, int offset, string? filter);
-        public SnapLine(SnapLineType type, int offset, string filter, SnapLinePriority priority);
+        public SnapLine(SnapLineType type, int offset, string? filter, SnapLinePriority priority);
-        public string Filter { get; }
+        public string? Filter { get; }
     }
 }
```

