Common Service Locator library

namespace Microsoft.Practices.ServiceLocation
{
 public interface IServiceLocator : IServiceProvider
    {
 object GetInstance(Type serviceType);
 object GetInstance(Type serviceType, string key);
        IEnumerable<object> GetAllInstances(Type serviceType);
        TService GetInstance<TService>();
        TService GetInstance<TService>(string key);
        IEnumerable<TService> GetAllInstances<TService>();
    }
}

namespace Microsoft.Practices.ServiceLocation
{
 public static class ServiceLocator
    {
 private static ServiceLocatorProvider currentProvider;

 public static IServiceLocator Current
        {
            get { return currentProvider(); }
        }

 public static void SetLocatorProvider(ServiceLocatorProvider newProvider)
        {
            currentProvider = newProvider;
        }
    }
}