docs: T getValueAtPosition(final int pos) {
      if (itemsSeen_ == 0) {
        throw new SketchesArgumentException("Requested element from empty reservoir.");
      } else if ((pos < 0) || (pos >= getNumSamples())) {
        throw new SketchesArgumentException("Requested position must be between 0 and "
                + getNumSamples() + ", " + "inclusive. Received: " + pos);
      }
  
      return data_.get(pos);
    }