code: public V get(boolean[] markHolder) {
          Pair<V> pair = this.pair;
          markHolder[0] = pair.mark;
          return pair.reference;
      }
docs: Returns the current values of both the reference and the mark.
  Typical usage is {@code boolean[1] holder; ref = v.get(holder); }.
  
  @param markHolder an array of size of at least one. On return,
  {@code markHolder[0]} will hold the value of the mark.
  @return the current value of the reference