What is Double Brace initialization in Java?

Question

What is Double Brace initialization syntax ({{ ... }}) in Java?

Answer 1

1- There is no such thing as double braces:
I'd like to point out that there is no such thing as double brace initialization. There is only normal traditional one brace initializaition block. Second braces block has nothing to do with initialization. Answers say that those two braces initialize something, but it is not like that.

2- It's not just about anonymous classes but all classes:
Almost all answers talk that it is a thing used when creating anonymous inner classes. I think that people reading those answers will get the impression that this is only used when creating anonymous inner classes. But it is used in all classes. Reading those answers it looks like is some brand new special feature dedicated to anonymous classes and I think that is misleading.

3- The purpose is just about placing brackets after each other, not new concept:
Going further, this question talks about situation when second opening bracket is just after first opening bracket. When used in normal class usually there is some code between two braces, but it is totally the same thing. So it is a matter of placing brackets. So I think we should not say that this is some new exciting thing, because this is the thing which we all know, but just written with some code between brackets. We should not create new concept called "double brace initialization".

4- Creating nested anonymous classes has nothing to do with two braces:
I don't agree with an argument that you create too many anonymous classes. You're not creating them because an initialization block, but just because you create them. They would be created even if you did not use two braces initialization so those problems would occur even without initialization... Initialization is not the factor which creates initialized objects.

Additionally we should not talk about problem created by using this non-existent thing "double brace initialization" or even by normal one bracket initialization, because described problems exist only because of creating anonymous class so it has nothing to do with original question. But all answers with give the readers impression that it is not fault of creating anonymous classes, but this evil (non-existent) thing called "double brace initialization".