<PackageReference Include="System.Text.Encodings.Web" Version="10.0.0-preview.1.25080.5" />

TextWriterExtensions

static class TextWriterExtensions
namespace System.IO { internal static class TextWriterExtensions { public static void WritePartialString(this TextWriter writer, string value, int offset, int count) { if (offset == 0 && count == value.Length) writer.Write(value); else { ReadOnlySpan<char> buffer = value.AsSpan(offset, count); writer.Write(buffer); } } } }