<PackageReference Include="Polly" Version="5.1.0" />

EmptyStruct

struct EmptyStruct
A null struct for policies and actions which do not return a TResult.
using System.Runtime.InteropServices; namespace Polly.Utilities { [StructLayout(LayoutKind.Sequential, Size = 1)] internal struct EmptyStruct { internal static readonly EmptyStruct Instance; } }