ListView.builder(
   itemCount: mockPersons.length,
   itemBuilder: (context, index) {
     final person = mockPersons.elementAt(index);
     final age = '${person.age} years old';
     return ListTile(
       title: Text(person.name),
       subtitle: Text(age),
       trailing: const Icon(
         Icons.arrow_forward_ios,
       ),
       onTap: () {
         // When a [ListTile] that represents a person is
         // tapped, push the detailsPageRouteName route
         // to the Navigator and pass the person's instance
         // to the route.
         Navigator.of(context).pushNamed(
           detailsPageRouteName,
           arguments: person,
         );
       },
     );
   },
 ),