调用Firebase.initializeApp()，但我已经在我的代码中有它了。

这个问题已经有了答案：

在Flutter和Firebase中没有创建默认的Firebase App \'[DEFAULT]\' - 调用Firebase.initializeApp()

所以我想用firebase制作一个flutter应用程序，它运行得很好，但是当我运行应用程序时，我会得到这个错误：

════════ Exception caught by widgets library ═══════════════════════════════════
The following FirebaseException was thrown building _BodyBuilder:
[core/no-app] No Firebase App '[DEFAULT]' has been created - call Firebase.initializeApp()
    The relevant error-causing widget was
    Scaffold
    package:app_with_firebase/main.dart:14
    When the exception was thrown, this was the stack
    #0      MethodChannelFirebase.app
    package:firebase_core_platform_interface/…/method_channel/method_channel_firebase.dart:122
    #1      Firebase.app
    package:firebase_core/src/firebase.dart:54
    #2      FirebaseAuth.instance
    package:firebase_auth/src/firebase_auth.dart:37
    #3      new AuthService
    package:app_with_firebase/Services/auth.dart:4
    #4      new _LoginPageState
    package:app_with_firebase/main.dart:29
    ...
    ════════════════════════════════════════════════════════════════════════════════

但问题是我已经在我的代码里有这行：

//import 'package:firebase_core/firebase_core.dart';
import 'package:flutter/material.dart';
import 'package:firebase_core/firebase_core.dart';
import 'Services/auth.dart';
void main() async {
  WidgetsFlutterBinding.ensureInitialized();
  Firebase.initializeApp();
  runApp(
    MaterialApp(
      debugShowCheckedModeBanner: false,
      home: Scaffold(
        body: LoginPage(),
      ),
    ),
  );
}

我该如何去掉这个错误？应用程序运行得很好，但这非常令人分心，任何帮助都将不胜感激，谢谢。