3rd one is a bit more cryptic. Let's take, for exa...

# language-proposals

[dmitry.petrov]

3rd one is a bit more cryptic.
Let's take, for example, java.lang.HashMap<int, int>. What does it's get method return if the key is absent?
It can't return null, because it's not an int.
It's actually mentioned here http://openjdk.java.net/jeps/218:

Null. Null is a valid value of every reference type, and is often used to represent "nothing is there." Primitive and value types, however, have no analogue of null. This is a challenge for methods like Map.get, which are defined to return null if the specified key cannot be found in the map.