问调用Laravel中未定义的方法App\User::role()

EN

use DB;
use Auth;
use Storage;

use App\Role;
use App\HasRoles;
use App\User;
use App\Profile;

$users = User::with('roles')->where('name', 'admin')->get();
return view('dashboard.users.index', compact('users')); 

use Illuminate\Notifications\Notifiable;
use Illuminate\Contracts\Auth\MustVerifyEmail;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable implements MustVerifyEmail
{
    use Notifiable, HasRoles;

    protected $fillable = [
        'name', 'email', 'phone_number', 'avatar', 'password', 'verification_code'
    ];

    protected $hidden = [
        'password', 'remember_token',
    ];

    protected $casts = [
        'email_verified_at' => 'datetime',
        'phone_verified_at' => 'datetime',
    ];

    public function profile()
    {
        return $this->hasOne('App\Profile', 'user_id','id');
    }

    public function mailingAdd()
    {
        return $this->hasOne('App\MailingAddress', 'user_id','id');
    }

@foreach($users->role as $item)
    <tr>
        <td>{{ $loop->iteration }}</td>
        <td><a href="{{ url('/dashboard/users', $item->id) }}">{{ $item->name }}</a></td>
        <td>{{ $item->email }}</td>
        <td>{{ $item->role()->name }}</td>
        <td>{{ $item->phone_number==null ? 'None' : $item->phone_number  }}</td>
        <td>
            @if($item->phone_verfied_at==null)
                <span class="badge badge-danger">not yet verified</span>
            @else
                <span class="badge badge-success">verified</span>
            @endif
        </td>
    </tr>
@endforeach     

@foreach($users as $user)
    {{ $user->name }}
    @foreach ($user->roles as $role)
        {{ $role->name }}
    @endforeach
@endforeach