🚧 remove new keyword to get inline with dart 2 code standard.

using_listview/lib/contact_page.dart

@@ -28,6 +28,6 @@ class ContactPage extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return new Scaffold(body: new ContactsList(_buildContactList()));
+    return Scaffold(body: ContactsList(_buildContactList()));
   }
 }

using_listview/lib/contactlist/contact_list.dart

@@ -9,15 +9,15 @@ class ContactsList extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return new ListView(
-      padding: new EdgeInsets.symmetric(vertical: 8.0),
+    return ListView(
+      padding: EdgeInsets.symmetric(vertical: 8.0),
       children: _buildContactsList(),
     );
   }
 
   List<ContactListItem> _buildContactsList() {
     return _contactModal
-        .map((contact) => new ContactListItem(contact))
+        .map((contact) => ContactListItem(contact))
         .toList();
   }
 }

using_listview/lib/contactlist/contact_list_item.dart

@@ -8,9 +8,9 @@ class ContactListItem extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return new ListTile(
-        leading: new CircleAvatar(child: new Text(_contactModal.fullName[0])),
-        title: new Text(_contactModal.fullName),
-        subtitle: new Text(_contactModal.email));
+    return ListTile(
+        leading: CircleAvatar(child: Text(_contactModal.fullName[0])),
+        title: Text(_contactModal.fullName),
+        subtitle: Text(_contactModal.email));
   }
 }

using_listview/lib/main.dart

@@ -2,13 +2,13 @@ import 'package:flutter/material.dart';
 import 'package:using_listview/contact_page.dart';
 
 void main() {
-  runApp(new MaterialApp(
+  runApp(MaterialApp(
     debugShowCheckedModeBanner: false,
-    home: new Scaffold(
-      appBar: new AppBar(
-        title: new Text("Using Listview"),
+    home: Scaffold(
+      appBar: AppBar(
+        title: Text("Using Listview"),
       ),
-      body: new ContactPage(),
+      body: ContactPage(),
     ),
   ));
 }