nsAString& aDest )
nsScannerSharedSubstring& aDest )
AppendUnicodeTo( const nsScannerIterator& aSrcStart,                 const nsScannerIterator& aSrcEnd,                 nsAString& aDest )  {    nsAString::iterator writer;    PRUint32 oldLength = aDest.Length();    aDest.SetLength(oldLength + Distance(aSrcStart, aSrcEnd));    aDest.BeginWriting(writer).advance(oldLength);    nsScannerIterator fromBegin(aSrcStart);        copy_string(fromBegin, aSrcEnd, writer);  }