fix nullable

PowerShell · CarloToso · Mar 21, 2023 · Mar 21, 2023 · Mar 21, 2023 · Mar 21, 2023
commit 3ecad716c36f16d33d1227dd33efdf971484e982
diff --git a/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs b/src/Microsoft.PowerShell.Commands.Utility/commands/utility/WebCmdlet/StreamHelper.cs
@@ -378,7 +378,7 @@ private static async Task<Encoding> GetStreamEncodingAsync(Stream stream, string
             return encoding;
         }
 
-        internal static string DecodeStream(Stream stream, string characterSet, out Encoding encoding, CancellationToken cancellationToken)
+        internal static string DecodeStream(Stream stream, string? characterSet, out Encoding encoding, CancellationToken cancellationToken)
         {
             encoding = GetStreamEncodingAsync(stream, characterSet, cancellationToken).GetAwaiter().GetResult();