what is a usage pattern for "static" in an interface?

[dennis luehring]

like:

public interface test
{
   public static void blub();
}

static class test_static: test
{
   private static void blub()
   {
      int i = 10;
   }
}

int main()
{
   test_static.blub();

   return 0;
}

any idea why static could makes sense in an interface? any example?

another thing:

why can i public "blub" in the interface and private it in the class?