public static SparseArray<Bundle> buildActionExtrasMap(List<Bundle> actionExtrasList) {
        SparseArray<Bundle> actionExtrasMap = null;
        for (int i = 0, count = actionExtrasList.size(); i < count; i++) {
            Bundle actionExtras = actionExtrasList.get(i);
            if (actionExtras != null) {
                if (actionExtrasMap == null) {
                    actionExtrasMap = new SparseArray<Bundle>();
                }
                actionExtrasMap.put(i, actionExtras);
            }
        }
        return actionExtrasMap;
    }
Return an SparseArray for action extras or null if none was needed.
android/android_framework/base/src/main/java/github/tornaco/android/thanos/core/compat/NotificationCompatJellybean.java