1--- ../../../libcore/ojluni/src/main/java/java/util/AbstractCollection.java	2019-05-31 10:36:26.634361294 -0700
2+++ src-ex/java/util/AbstractCollection.java	2019-11-18 13:04:48.253575013 -0800
3@@ -63,7 +63,13 @@
4      * Sole constructor.  (For invocation by subclass constructors, typically
5      * implicit.)
6      */
7+    public static volatile int TOTAL_COUNT;
8+    public int cnt;
9+
10     protected AbstractCollection() {
11+      synchronized (Collection.class) {
12+        cnt = ++TOTAL_COUNT;
13+      }
14     }
15
16     // Query Operations
17