Mock with MediatR and xUnit

I have a project that I am implementing the Unit Tests with the Mock Framework, in this project I have implemented CQRS using MediatR.

Follow the test code

public RegistrarMaanaimComandTest()
{
    [Fact]
    public void RegistrarLocal_RetornoSucesso()
    {

           var mediatorMock = new Mock<IMediatorHandler>();
           var localCommandHandler = new LocalCommandHandler(mediatorMock);
           var local = new Local();
           var registrarLocal = new RegistrarLocalComando(local);
           var localRegistradoComSucessoEvento = new LocalRegistradoComSucessoEvento(nome: nome, sigla: sigla, limite: limite);

           mediatorMock b.Setup(b =>.RaiseEvent(localRegistradoComSucessoEvento));

           localCommandHandler.Handle(registrarLocal);

    }
}

public interface IMediatorHandler
{
    Task RaiseEvent<T>(T evento) where T : Event;
    Task SendCommand<T>(T comando) where T : Command;
}



public class LocalCommandHandler : CommandHandler,INotificationHandler<RegistrarLocalComando>
{

   public LocalCommandHandler(IMediatorHandler mediator)
   {
      _mediator = mediator;
   }

   public Task Handle(RegistrarLocalComando message, CancellationToken cancellationToken)
   {

    var localRegistradoComSucessoEvento = new LocalRegistradoComSucessoEvento(nome: message.Nome, sigla: message.Sigla, limite: message.Limite);

    _mediator.RaiseEvent(localRegistradoComSucessoEvento);

    return Task.CompletedTask;       

   }

}

When I run I get the following error:

  

Moq.MockException     HResult = 0x80131500     Message =   Expected invocation on the mock once, but was 0 times: m = > m.RaiseEvent (Local Registered with Successful Event)

     

Configured setups:   x = > x.RaiseEvent (Local Registered with Successful Event)

     Performed invocations:   IMediatorHandler.RaiseEvent (Local Registered with Successful Event)