public ResolutionRules.ResolveUnregisteredService UseRegistrationsFrom(IRegistry registry) { ResolutionRules.ResolveUnregisteredService useRegistryRule = (request, _) => registry.GetOrAddFactory(request, IfUnresolved.ReturnNull); ResolutionRules.UnregisteredServices = ResolutionRules.UnregisteredServices.Append(useRegistryRule); return useRegistryRule; }