class Error {
 const Error();

 /**
  * Safely convert a value to a [String] description.
  *
  * The conversion is guaranteed to not throw, so it won't use the object's
  * toString method.
  */
 static String safeToString(Object object) {
   if (object is int || object is double || object is bool || null == object) {
     return object.toString();
   }
   if (object is String) {
     // TODO(ahe): Remove backslash when http://dartbug.com/4995 is fixed.
     String string = object;
     const backslash = '\\';
     String escaped = string
       .replaceAll('$backslash', '$backslash$backslash')
       .replaceAll('\n', '${backslash}n')
       .replaceAll('\r', '${backslash}r')
       .replaceAll('"',  '$backslash"');
     return '"$escaped"';
   }
   return _objectToString(object);
 }

 external static String _objectToString(Object object);
}