<PackageReference Include="System.Collections.Immutable" Version="11.0.0-preview.7.26381.103" />

System.Collections.Frozen.FrozenHashTable

namespace System.Collections.Frozen { internal readonly struct FrozenHashTable { public int Count { get; } public static FrozenHashTable Create(Span<int> hashCodes, bool hashCodesAreUnique = false); public void FindMatchingEntries(int hashCode, out int startIndex, out int endIndex); } }