code: @Override
      @SuppressWarnings("unchecked")
      @ConstantTime
      public void clear() {
          root = null;
          size = 0;
          decreasePool = (Node[]) Array.newInstance(Node.class, DEFAULT_DECREASE_POOL_SIZE);
          decreasePoolSize = 0;
          decreasePoolMinPos = 0;
      }
docs: {@inheritDoc}