Add [NotNull] annotation

osu.Game.Rulesets.Catch/UI/CatcherTrailDisplay.cs

@@ -2,6 +2,7 @@
 // See the LICENCE file in the repository root for full licence text.
 
 using System;
+using JetBrains.Annotations;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Animations;
 using osu.Framework.Graphics.Containers;
@@ -73,7 +74,7 @@ namespace osu.Game.Rulesets.Catch.UI
             }
         }
 
-        public CatcherTrailDisplay(Catcher catcher)
+        public CatcherTrailDisplay([NotNull] Catcher catcher)
         {
             this.catcher = catcher ?? throw new ArgumentNullException(nameof(catcher));