# System.IO

``` diff
 namespace System.IO {
     public static class Path {
+        public static string Combine(ReadOnlySpan<string> paths);
+        public static string Join(ReadOnlySpan<string?> paths);
     }
     public class StreamWriter : TextWriter {
+        public override void Write(string format, ReadOnlySpan<object?> arg);
+        public override void WriteLine(string format, ReadOnlySpan<object?> arg);
     }
     public abstract class TextWriter : MarshalByRefObject, IAsyncDisposable, IDisposable {
+        public virtual void Write(string format, ReadOnlySpan<object?> arg);
+        public virtual void WriteLine(string format, ReadOnlySpan<object?> arg);
     }
 }
```

