TestClusterBuilder - Dependency Injection

[notour]

I need to make a single grain execution unit test.
This one need a specific service in pass by dependency injection in the constructor.

To control my test i need to inject a singleton instance.
I achieved to inject test type using ISiloConfigurator && IHostConfigurator.

Is it possible to inject test instance (Mock) during a test using TestClusterBuilder.
Like :

       var def = new Definition() ...

       var defintionProviderMock = new Mock<IDefinitionProvider>();

        var builder = new TestClusterBuilder();

       // Inject defintionProviderMock 

        var cluster = builder.Build();
        cluster.Deploy();

        var executor = cluster.GrainFactory.GetGrain<ICustomGrain>(def.Uid);

        var result = await executor.RunAsync<string[], string>(s_emailSampleTest);

        Check.That(result).IsNotNull().And.ContainsExactly(s_emailA, s_emailB).And.CountIs(2);

        cluster.StopAllSilos();