Hi
How can I prevent inheritance of some methods or properties in derived classes?!

public class BaseClass : Collection   
{  
    //Some operations...  
    //Should not let derived classes inherit 'Add' method.  
}

public class DerivedClass : BaseClass      
{        
    public void DoSomething(int Item)      
    {      
        this.Add(Item); // Error: No such method should exist...      
    }      
}