Undefined name 'contacts'.

import 'package:bytebank2/database/app_database.dart';
import 'package:bytebank2/models/contact.dart';
import 'package:bytebank2/screens/contact_form.dart';
import 'package:flutter/material.dart';

class ContactList extends StatefulWidget {
  @override
  State<ContactList> createState() => _ContactListState();
}

class _ContactListState extends State<ContactList> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Contacts'),
      ),
      body: FutureBuilder(
        future: findAll(),
        builder: (context, snapshot) {
          return ListView.builder(
            itemBuilder: (BuildContext context, int index) {
              final List<Contact>? contacts = snapshot.data as List<Contact>?;
              final Contact contact = contacts![index];
              return _ContactItem(contact);
            },
            itemCount: contacts.legth, (O ERRO ESTÁ SENDO APONTADO AQUI)

          );
        },),
    floatingActionButton:
    FloatingActionButton(
      onPressed: () {
        Navigator.of(context)
            .push(MaterialPageRoute(
          builder: (context) => ContactForm(),
        ))
            .then((newContact) => debugPrint(newContact.toString()),);
      },
      child: Icon(Icons.add),
    )
    ,
    );
  }
}

class _ContactItem extends StatelessWidget {
  final Contact contact;

  _ContactItem(this.contact);

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Card(
      child: ListTile(
        title: Text(
          contact.name,
          style: TextStyle(fontSize: 24),
        ),
        subtitle: Text(
          contact.accountNumber.toString(),
          style: TextStyle(fontSize: 16),
        ),
      ),
    );
  }
}

Basicamente está no msm lugar que o do professor mais quando eu executo da esse erro não sei o porque.