Inline HashMap initialization using static initializer

import java.util.*;

public class Scratch {
    public static void main(String[] args) {
        HashMap<String, Integer> stuff = new HashMap<String, Integer>() {{
            put("A", 1);
            put("B", 2);
            put("C", 3);
        }};

        for(String key : stuff.keySet()) {
            System.out.println(key + ": " + stuff.get(key));
        }
    }
}