如何在dart中将List<List<Map<String、String>>>转换为List<List<CustomObject>>

class CustomObject {
  String key1;
  String key2;

  CustomObject(this.key1, this.key2);
}

List<List<Map<String, String>>> originalList = [
  [
    {'key1': 'value1', 'key2': 'value2'},
    {'key1': 'value3', 'key2': 'value4'}
  ],
  [
    {'key1': 'value5', 'key2': 'value6'},
    {'key1': 'value7', 'key2': 'value8'}
  ]
];

List<List<CustomObject>> convertedList = originalList.map((list) {
  return list.map((map) {
    return CustomObject(map['key1'], map['key2']);
  }).toList();
}).toList();