Sealed methods

When an instance method declaration includes a sealed modifier, that method is said to be a sealed method. A sealed method overrides an inherited virtual method with the same signature. An override method can also be marked with the sealed modifier. Use of this modifier prevents a derived class from further overriding the method.
[Example: The example using System; class A { public virtual void F() { Console.WriteLine("A.F"); } public virtual void G() { Console.WriteLine("A.G"); } } class B: A { sealed override public void F() { Console.WriteLine("B.F"); } override public void G() { Console.WriteLine("B.G"); } } class C: B { override public void G() { Console.WriteLine("C.G"); } } the class B provides two override methods: an F method that has the sealed modifier and a G method that does not. B's use of the sealed modifier prevents C from further overriding F. end example]