Update PositionSnapshot.java

Hi,
Don't merge this, I'm working on this one but I'm having problems retrieving elements in HashMap positionMap by using a key.

I can't get it to work!
As you see my hasmap has 1 element with key 1..but when I'm getting the element with key one it returns null, if I ask the hashmap if it has an element with key 1 returns false!!!

Obviously I've tried with different keys..too.
But I can't get it to work....