user.photoUrl, user.email에 빨간줄

선생님 질문이 있습니다.

 final FirebaseUser user;

HomePage(this.user);

firebase user 선언 했는데 

user 밑줄로 빨간 줄 생기네요

child: CircleAvatar(
  backgroundImage: NetworkImage(user.photoUrl),
),

마우스로 빨간줄 위에 체크해보니

Undefined name 이라고 뜨네요 

밑에는 혹시나 몰라서 코딩적은 것 남깁니다.

import 'package:firebase_auth/firebase_auth.dart';
import 'package:flutter/material.dart';

class HomePage extends StatelessWidget {
  final FirebaseUser user;
  HomePage(this.user);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.white,
        title: Text(
          'Instagram Clon',
          style: TextStyle(
            fontWeight: FontWeight.w700,
            fontSize: 20,
          ),
        ),
      ),
      body: _buildBody(),
    );
  }
}

Widget _buildBody() {
  return Padding(
    padding: const EdgeInsets.all(8.0),
    child: SafeArea(
      child: SingleChildScrollView(
        child: Center(
          child: Column(
            mainAxisAlignment: MainAxisAlignment.center,
            children: <Widget>[
              Text(
                'Instagram에 오신걸 환영합니다.',
                style: TextStyle(fontSize: 24.0, fontWeight: FontWeight.w500),
              ),
              Padding(padding: EdgeInsets.all(8.0)),
              Text('사진과 동영상을 보려면 팔로우 하세요'),
              Padding(padding: EdgeInsets.all(16.0)),
              SizedBox(
                width: 380,
                child: Card(
                  elevation: 4.0,
                  margin: EdgeInsets.all(20.0),
                  child: Padding(
                    padding: const EdgeInsets.all(8.0),
                    child: Column(
                      children: <Widget>[
                        Padding(padding: EdgeInsets.all(4.0)),
                        SizedBox(
                          width: 80.0,
                          height: 80.0,
                          child: CircleAvatar(
                            backgroundImage: NetworkImage(user.photoUrl),
                          ),
                        ),
                        Padding(padding: EdgeInsets.all(8.0)),
                        Text(
                          user.email,
                          style: TextStyle(fontWeight: FontWeight.bold),
                        ),
                        Text('Maik'),
                        Padding(padding: EdgeInsets.all(8.0)),
                        Row(
                          mainAxisAlignment: MainAxisAlignment.center,
                          children: <Widget>[
                            SizedBox(
                              width: 70.0,
                              height: 70.0,
                              child: Image.network(
                                  'https://images.unsplash.com/photo-1587831663705-fe11c6db99b4?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=500&q=60',
                                  fit: BoxFit.cover),
                            ),
                            Padding(padding: EdgeInsets.all(1.0)),
                            SizedBox(
                              width: 70.0,
                              height: 70.0,
                              child: Image.network(
                                  'https://images.unsplash.com/photo-1587747305800-adc0ebe7cf86?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=500&q=60',
                                  fit: BoxFit.cover),
                            ),
                            Padding(padding: EdgeInsets.all(1.0)),
                            SizedBox(
                              width: 70.0,
                              height: 70.0,
                              child: Image.network(
                                  'https://images.unsplash.com/photo-1587751034030-0dd59564377f?ixlib=rb-1.2.1&ixid=eyJhcHBfaWQiOjEyMDd9&auto=format&fit=crop&w=500&q=60',
                                  fit: BoxFit.cover),
                            ),
                          ],
                        ),
                        Padding(padding: EdgeInsets.all(4.0)),
                        Text('Facebook 친구'),
                        Padding(padding: EdgeInsets.all(4.0)),
                        RaisedButton(
                          color: Colors.blueAccent,
                          onPressed: () {},
                          child: Text(
                            '팔로우',
                            style: TextStyle(color: Colors.white),
                          ),
                        ),
                        Padding(padding: EdgeInsets.all(8.0)),
                      ],
                    ),
                  ),
                ),
              )
            ],
          ),
        ),
      ),
    ),
  );
}