nsWritableFragment<CharT> fragment; GetWritableFragment(fragment, kLastFragment); return nsWritingIterator<CharT>(fragment, fragment.mEnd, *this);
aResult.mOwningString = this; GetWritableFragment(aResult.mFragment, kLastFragment); aResult.mPosition = aResult.mFragment.mEnd;  return aResult;
      EndWriting()        {          nsWritableFragment<CharT> fragment;          GetWritableFragment(fragment, kLastFragment);          return nsWritingIterator<CharT>(fragment, fragment.mEnd, *this);        }