namespace MyTestLib
{
   public class MyTestClass
   {
      private int _x;
      public MyTestClass(int inNumber) { SetNumber(inNumber); }

      public int GetNumber()
      {
         Console.WriteLine(string.Format(".NET MyTestClass.GetNumber: {0}", _x));
         return _x;
      }
      public void SetNumber(int inNumber)
      {
         _x = inNumber;
         Console.WriteLine(string.Format(".NET MyTestClass.SetNumber: {0}", _x));
      }

      protected virtual void OnUseNumber(int inNumber) { }

      public void UseNumber(int inNumber)
      {
         Console.WriteLine(string.Format(".NET MyTestClass.UseNumber: {0}", inNumber));
         OnUseNumber(inNumber);
      }
   }

   public class MyTestClass2 : MyTestClass
   {
      MyTestClass2() : base(55) { }
      protected override void OnUseNumber(int inNumber)
      {
         SetNumber(inNumber * 4000);
         Console.WriteLine(string.Format("MyTestClass2.OnUseNumber: {0}", GetNumber()));
      }
   }
}