A DESCRIPTION OF THE REQUEST :
We can initialize Arrays like  Integer i = {1,2,3,4}. However, same thing is possible on Collections like List, Set and Maps. I would recommend to allow this feature on Collections too.

For example:
List<Integer> list = new ArrayList(){1,2,3,4} or new ArrayList(1,2,3,4,...).
Map<String,Integer> map = new HashMap(){ "1":1,"2":2,"3":3,..}

This will be very helpful especial, when writing testing cases, and we have to create parallel collections to assert/validate test cases 


JUSTIFICATION :
When we have to create a Collection with small/medium amount of known data, especially when writing test cases. we have to call add() again and again many times or create a parallel collection to assert the test case values. This will result in lot of code in Fixture, this feature will be very handy and can solve this problem very effectively