# System

``` diff
 namespace System {
     public static class Nullable {
-        public static ref readonly T GetValueRefOrDefaultRef<T>(in T? nullable) where T : struct;
+        public static ref readonly T GetValueRefOrDefaultRef<T>(ref readonly T? nullable) where T : struct;
     }
     [NativeMarshallingAttribute(typeof(ReadOnlySpanMarshaller<,>))]
     public readonly ref struct ReadOnlySpan<T> {
-        public ReadOnlySpan(in T reference);
+        public ReadOnlySpan(ref readonly T reference);
     }
     public sealed class TimeZoneInfo : IDeserializationCallback, IEquatable<TimeZoneInfo?>, ISerializable {
+        public static ReadOnlyCollection<TimeZoneInfo> GetSystemTimeZones(bool skipSorting);
     }
 }
```

