public static void Go(){
MyUnion2 u2 = new MyUnion2();
MyUnion1 u1 = new MyUnion1();
u1.i = 0;
u1.o.o = new Bar();
Console.WriteLine("BEFORE: u1.o.o.getI(): {0}. (EXPECT 1)",u1.o.o.getI());
u2.i = 0;
u2.o.o = new Foo();
// write the Foo's objref value now in u2.o into the int field of u1,
// thereby overwriting the Bar objref that had been in u1.o.
u1.i = u2.i;
// If u1.o.o.getI() returns 42, that means that we were able to write to a private
// member variable of Bar, a huge security problem!
int curI = u1.o.o.getI();
Console.WriteLine("AFTER: u1.o.o.getI(): {0}. (BUG if 42)",curI);
}
