# System.Diagnostics

``` diff
 namespace System.Diagnostics {
-    public readonly struct CounterSample
+    public readonly struct CounterSample : IEquatable<CounterSample>
     public sealed class PerformanceCounter : Component, ISupportInitialize {
-        [ObsoleteAttribute("This field has been deprecated and is not used. Use machine.config or an application configuration file to set the size of the PerformanceCounter file mapping instead.")]
-        public static int DefaultFileMappingSize;
+        [ObsoleteAttribute("PerformanceCounter.DefaultFileMappingSize has been deprecated and is not used. Use machine.config or an application configuration file to set the size of the PerformanceCounter file mapping instead.")]
+        public static int DefaultFileMappingSize;
     }
+    public static class TraceConfiguration {
+        public static void Register();
+    }
 }
```

