class TestHandler : EventHandler
{
    protected int a; // play variable

    virtual protected void TestSmth()
    {
        a = 1; // works
    }
}

class TestHandler2 : TestHandler
{
    override void TestSmth()
    {
        a = 11;
    }

    void TestSmth2()
    {
        a = 2; // works
    }
}

class TestHandler3 : TestHandler
{
    TestHandler2 h2;

    void TestSmth3()
    {
        h2.a = 8; // works
    }
}

class TestHandler4 : EventHandler
{
    TestHandler h1;
    TestHandler2 h2;

    void TestSmth3()
    {
        h1.TestSmth(); // failure
        h2.TestSmth(); // failure
        h1.a = 4; // failure
        h2.a = 3; // failure
    }
}