<PackageReference Include="System.ServiceModel.Primitives" Version="8.1.1" />

System.ServiceModel.Channels.FaultHelper

abstract class FaultHelper
namespace System.ServiceModel.Channels { internal abstract class FaultHelper { protected object ThisLock { get; } protected FaultHelper(); public abstract void Abort(); public static bool AddressReply(Message message, Message faultMessage); public abstract Task CloseAsync(TimeSpan timeout); public abstract Task SendFaultAsync(IReliableChannelBinder binder, RequestContext requestContext, Message faultMessage); } }