title: Is is correct to use Future builder inside a streambuilder in Flutter
body: <p>My Requirement is such that whenever a user verifies with a phonenumber it will check in Firebase whether the document id  which is set as the phone number of the user if previously logged in ,exists or not if exists then Go to HomePage if it doesnot then Navigate to AccountVerification Page.</p>
  <p>Also if the user is already logged in but didnot verify closes the app and then open the app then there are two situations First the user has verified the account details or has  not verified during the verification process. In that case I will check the same whether the document id which is set to Phone number of the user exists or not if exist then go to HomePage else AccountVerification page.
  This is my code this is not working perfectly. Could anyone suggest me what should be the right approch</p>
  <pre><code>void main() {
    runApp(MyApp());
  }
  
  class MyApp extends StatefulWidget {
    @override
    _MyAppState createState() =&gt; _MyAppState();
  }
  
  class _MyAppState extends State&lt;MyApp&gt; {
  
    var globalNumber;
    var Number;
    Firestore firestore = Firestore.instance;
  
  
    @override
    void initState() {
      // TODO: implement initState
      super.initState();
      getCurrentUser();
  
  
  
    }
  
    @override
    Widget build(BuildContext context) {
      print(globalNumber);
      return MaterialApp(
        debugShowCheckedModeBanner: false,
        home: StreamBuilder&lt;Object&gt;(
          stream: FirebaseAuth.instance.onAuthStateChanged,
            builder: (BuildContext context, snapshot) {
              if (snapshot.hasData) {
                return FutureBuilder(
                    future: Future.wait([
  
                      firestore.collection('users').document(globalNumber).get()
  
                    ]),
                    builder: (BuildContext context,
                        AsyncSnapshot&lt;List&gt; snapshot) {
                      DocumentSnapshot doc = snapshot.data[0];
                      if(snapshot.hasData) {
                        if (doc.exists) {
                          return HomePage();
                        }
                        return AccountDetialsPage();
                      }
                      else{
                        return Container(child: Text('Loading'));
                      }
                    }
                );
              } else {
                return Phoneverification();
              }
            }),
      ) ;
    }
  
    getCurrentUser() async{
  
      final FirebaseAuth _auth = FirebaseAuth.instance;
      final FirebaseUser user = await _auth.currentUser();
      final uid = user.uid;
      globalNumber = user.phoneNumber;
      
      // Similarly we can get email as well
      //final uemail = user.email;
      print(uid);
  
    }
  
  }
  </code></pre>