Handler 2

gistfile1.cs

public interface ISomeService { string DoSomething(); }
public class SomeService : ISomeService { public string DoSomething() { return string.Empty; } }

public class Foo
{
    private readonly ISomeService _someService;
    public Foo(ISomeService someService) { _someService = someService; }
    public string Render()
    {
        return "this is a foo" + _someService.DoSomething();
    }
}