Substring( const nsAString::const_iterator& aStart, const nsAString::const_iterator& aEnd )
Substring( const nsASingleFragmentString::const_char_iterator& aStart, const nsASingleFragmentString::const_char_iterator& aEnd )
Substring( const nsAString::const_iterator& aStart, const nsAString::const_iterator& aEnd )  {    return nsDependentSubstring(aStart, aEnd);  }