nsWritingIterator<CharT> result; return EndWriting(result);
aResult.mOwningString = this; GetWritableFragment(aResult.mFragment, kLastFragment); aResult.mPosition = aResult.mFragment.mEnd;  return aResult;
      EndWriting()        {          nsWritingIterator<CharT> result;          return EndWriting(result); // copies (since I return a value, not a reference)        }