如何使用Dart/Flutter在Cloud Firestore中存储一个简单的矩阵？

import 'package:cloud_firestore/cloud_firestore.dart';

final FirebaseFirestore firestore = FirebaseFirestore.instance;

class Matrix {
  final List<List<int>> data;

  Matrix(this.data);
}

final String collectionName = 'matrices';
final String documentName = 'matrix1';

Matrix matrix = Matrix([
  [1, 2, 3],
  [4, 5, 6],
  [7, 8, 9],
]);

void storeMatrix() async {
  await firestore.collection(collectionName).doc(documentName).set({
    'data': matrix.data,
  });
}

void retrieveMatrix() async {
  DocumentSnapshot snapshot =
      await firestore.collection(collectionName).doc(documentName).get();

  if (snapshot.exists) {
    Matrix retrievedMatrix = Matrix(snapshot.data()['data']);
    print(retrievedMatrix.data);
  }
}