<PackageReference Include="System.Collections.Immutable" Version="11.0.0-preview.2.26159.112" />

System.Collections.Frozen.Hashing

static class Hashing
namespace System.Collections.Frozen { internal static class Hashing { public static int GetHashCodeOrdinal(ReadOnlySpan<char> s); public static int GetHashCodeOrdinalIgnoreCaseAscii(ReadOnlySpan<char> s); public static int GetHashCodeOrdinalIgnoreCase(ReadOnlySpan<char> s); } }