class BaseClass : ICloneable
{
    // Explicit implementation so that the recommended methods will be used instead.
    object ICloneable.Clone(CloneContext context)
    {
        var clone = (BaseClass)MemberwiseClone();
        clone.CopyFrom(this, context);
        return clone;
    }
    
    // Protected method which should only be called by Clone.
    protected virtual void InitializeClone(CloneContext context)
    {
        // Alter any necessary BaseClass fields according to the context.
    }
}

class DerivedClass : BaseClass
{
    protected override void InitializeClone(CloneContext context)
    {
        base.CopyFrom(copyFrom, context);
        
        var derived = (DerivedClass)copyFrom;
        // Alter any necessary DerivedClass fields according to the context.
    }
}