dart:js IntersectionObserver unwrapping bug

main.dart

import 'dart:js';
import 'dart:html';

main() {
  printJsObject(document.body);
  var o = IntersectionObserver((entries, observer) {
    printJsObject(observer);
    printJsObject(JsObject.fromBrowserObject(observer));
    for (final entry in entries) {
      printJsObject(entry);
      printJsObject(JsObject.fromBrowserObject(entry));
      
      //final visible = _isVisible.apply([entry]);
      //final visible = _isVisible.apply([JsObject.fromBrowserObject(entry)]);
      final visible = JsObject.fromBrowserObject(entry)['isVisible'];
      
      print('_isVisible($entry) = $visible');
    }
  }, {'trackVisibility': 'true', 'delay': '500'});
  o.observe(document.body);
}

printJsObject(o) => (JsObject(context['Function'], ['''
  const o = arguments[0];
  console.log(o);
  console.log(Object.getPrototypeOf(o));
  console.log(Object.keys(Object.getPrototypeOf(o)));
  console.log('');
''']) as JsFunction).apply([o]);

final JsFunction _isVisible = JsObject(context['Function'], ['''
  const entry = arguments[0];
  console.log(entry);
  console.log(Object.getPrototypeOf(entry));
  console.log(Object.keys(Object.getPrototypeOf(entry)));
  return entry.isVisible;
''']);