C# quiz: 4/?

Given the following code:

    internal class Test {
        public int Foo { get; set; }
        public int Bar { get; set; }

#if CUSTOM
        public override int GetHashCode() {
            return Foo.GetHashCode() ^ Bar.GetHashCode();
        }

        public override bool Equals(object obj) {
            if (object.ReferenceEquals(obj, null)) return false;
            Test t = obj as Test;
            if (t != default(Test)) {
                return (Foo == t.Foo) && (Bar == t.Bar);
            }
            return false;
        }
#endif
    }

and the following test code:

            Dictionary<Test, string> dict = new Dictionary<Test, string>();
            Test foo = new Test { Foo = 1, Bar = 2 };
            dict[foo] = "Hello World";
            foo.Bar = 42;
            if (dict.ContainsKey(foo)) {
                Console.WriteLine("it's there");
            } else {
                Console.WriteLine("it's not");
            }

Answer the following questions:

1. With CUSTOM not defined, what does the test code print?


2. If CUSTOM is defined, does it change the outcome?


3. What if Test is changed to a struct and CUSTOM is not defined, what is the output?


4. If Test is a struct and CUSTOM is defined, what happens?