class MyBase
{
    MyBase()
    {
        Record();
    }

    void Record()
    {
        /// this line is able to handle every object
        Recorder.Process(this);
    }
}

class DerivedA : MyBase
{
    public int SpecialPropertyOfA { get; set; }
    DerivedA(int specialPropertyOfA)
    {
        SpecialPropertyOfA = specialPropertyOfA;
    }
}

class DerivedB : MyBase
{
    public string SpecialPropertyOfB { get; set; }
    DerivedA(string specialPropertyOfB)
    {
        SpecialPropertyOfB = specialPropertyOfB;
    }
}