Stashbox by Peter Csajtai

<PackageReference Include="Stashbox" Version="5.8.2" />

 RegistrationConfigurator<TService, TImplementation>

public class RegistrationConfigurator<TService, TImplementation> : FluentServiceConfigurator<TService, TImplementation, RegistrationConfigurator<TService, TImplementation>> where TImplementation : TService
Represents the generic fluent service registration api.
public RegistrationConfigurator<TService, TImplementation> WithInstance(TService instance, bool wireUp = false)

Sets an instance as the resolution target of the registration.