# System.Net.Http.Headers

``` diff
 namespace System.Net.Http.Headers {
     [NullableAttribute((byte)0)]
     [NullableContextAttribute((byte)1)]
     public sealed class HttpRequestHeaders : HttpHeaders {
+        [NullableAttribute((byte)2)]
+        public string? Protocol { [NullableContextAttribute((byte)2)] get; [NullableContextAttribute((byte)2)] set; }
     }
 }
```

