chore: use file-scoped namespace

src/Shared/HandyControl_Shared/Interactivity/Behavior/BehaviorCollection.cs

@@ -1,42 +1,41 @@
 using System.Windows;
 
-namespace HandyControl.Interactivity
+namespace HandyControl.Interactivity;
+
+public sealed class BehaviorCollection : AttachableCollection<Behavior>
 {
-    public sealed class BehaviorCollection : AttachableCollection<Behavior>
+    internal BehaviorCollection()
     {
-        internal BehaviorCollection()
-        {
-        }
-
-        protected override void OnAttached()
-        {
-            foreach (var behavior in this)
-                behavior.Attach(AssociatedObject);
-        }
-
-        protected override void OnDetaching()
-        {
-            foreach (var behavior in this)
-                behavior.Detach();
-        }
-
-        internal override void ItemAdded(Behavior item)
-        {
-            if (item == null || AssociatedObject == null)
-                return;
-            item.Attach(AssociatedObject);
-        }
-
-        internal override void ItemRemoved(Behavior item)
-        {
-            if (((IAttachedObject) item)?.AssociatedObject == null)
-                return;
-            item.Detach();
-        }
-
-        protected override Freezable CreateInstanceCore()
-        {
-            return new BehaviorCollection();
-        }
     }
-}
+
+    protected override void OnAttached()
+    {
+        foreach (var behavior in this)
+            behavior.Attach(AssociatedObject);
+    }
+
+    protected override void OnDetaching()
+    {
+        foreach (var behavior in this)
+            behavior.Detach();
+    }
+
+    internal override void ItemAdded(Behavior item)
+    {
+        if (item == null || AssociatedObject == null)
+            return;
+        item.Attach(AssociatedObject);
+    }
+
+    internal override void ItemRemoved(Behavior item)
+    {
+        if (((IAttachedObject) item)?.AssociatedObject == null)
+            return;
+        item.Detach();
+    }
+
+    protected override Freezable CreateInstanceCore()
+    {
+        return new BehaviorCollection();
+    }
+}