This proposal is not intended to add support for general-purpose custom initializer syntax for any kind of object, nor is it intended to allow for custom DSLs in Java. This is for simple shorthand:
Map<String, Object> values = { "a": "alpha", "b": "beta", null: this };
var list = ArrayList<String> { "a", "b", "c" };
Set checked = HashSet<> { NORTH, SOUTH, NORTHWEST, };