anchor.diff:  * +Vector+ – deprecated
   |
   * +CopyOnWriteArrayList+ – seldom updated, often traversed
  +|=====
  +
  +
  +Collections implementations
  +---------------------------
  +
  +[options="header",cols="<1h,2*<3a"]
  +|=====
  +| {nbsp} ^| Single threaded ^| Concurrent
   | Queues / deques |
   * +ArrayDeque+ – generic array-based
   * +Stack+ – deprecated
  
positive.code: |
  * +ConcurrentHashMap+ – generic concurrent map
  * +ConcurrentSkipListMap+ – sorted concurrent map
  | Set |
  * +HashSet+ – generic set
  * +EnumSet+ – set of enums
  
negative.code: * +LinkedTransferQueue+ – may transfer elements w/o storing
  * +PriorityBlockingQueue+ – concurrent PriorityQueue
  * +SynchronousQueue+ – Exchanger with Queue interface
  |=====
  
  
  Collections implementations
  ---------------------------
  
  [options="header",cols="<1h,2*<3a"]
  |=====
  | {nbsp} ^| Single threaded ^| Concurrent
  | Maps |
  * +HashMap+ – generic map
  * +EnumMap+ – enum keys
  