code: final void swapPointers(int indexA, int indexB) {
      assert indexA >= 0 && indexA < valuesHeld;
      assert indexB >= 0 && indexB < valuesHeld;
  
      ByteBuffer a = copyPointer(indexA);
      ByteBuffer b = readPointer(indexB);
      writePointer(indexA, b);
      writePointer(indexB, a);
    }
docs: Place the pointer at indexA in indexB and vice versa.