<PackageReference Include="NETStandard.Library" Version="2.0.0-preview2-25401-01" />

System.Runtime.InteropServices.ComEventsHelper

public static class ComEventsHelper
namespace System.Runtime.InteropServices { public static class ComEventsHelper { public static void Combine(object rcw, Guid iid, int dispid, Delegate d); public static Delegate Remove(object rcw, Guid iid, int dispid, Delegate d); } }