public abstract class BasePageSingletonDerived<S, M> : ThreadSafeNestedContructorsBaseSingleton<S>
    where M : BasePageElementMap, new()
    where S : BasePageSingletonDerived<S, M>
{
    protected M Map
    {
        get
        {
            return new M();
        }
    }

    public virtual void Navigate(string url = "")
    {
        Driver.Browser.Navigate().GoToUrl(string.Concat(url));
    }
}

public abstract class BasePageSingletonDerived<S, M, V> : BasePageSingletonDerived<S, M>
    where M : BasePageElementMap, new()
    where V : BasePageValidator<M>, new()
    where S : BasePageSingletonDerived<S, M, V>
{
    public V Validate()
    {
        return new V();
    }
}