Inheritance Issue/Question

[Rob Steele]

Have the following code below that compiles but throws an invalid case exception (As expected). My problem is I need to be able to case and object of type Test into a object of type Test2. I am unable to use an implicit or explicit operator user defined case because it is not allowed to/from a base class. BUT, if while debugging TestIt I type into the Command window z = (Test2) y or x = (Test2) y it works?!?! What mechanism is the Command window using to do the casting of the objects and is it possible for me to recreate/reuse this method?

public class Test
{
public Test() {}

public int myValue = 1;
}

public class Test2 : Test
{
public Test2() { base.myValue = 2; }
}

public class Test3
{
public Test3() {}

public void TestIt()
{
Test2 x = new Test2();
Test y = new Test();
Test2 z = (Test2) y;
}
}