anchor.diff:  /// (see: https://github.com/dart-lang/sdk/issues/25053).
   ///
   /// __Defined in this package's React JS files.__
  +@Deprecated('5.0.0')
   final _GetPropertyFn getProperty = (() {
     try {
       // If this throws, then the JS function isn't available.
  
positive.code: 
    return jsMap;
  }
  
negative.code:       'cannot be used as expected. $message';
  }
  
  /// __Deprecated:__ Use [js_util.getProperty] instead.
  ///
  /// Returns the property at the given [_GetPropertyFn.key] on the
  /// specified JavaScript object [_GetPropertyFn.jsObj]
  ///
  