在Laravel中从Excel导入数据时，有没有附加关系(一对一、一对多、多对多)的方法？

use Maatwebsite\Excel\Facades\Excel;
use App\User;
use App\Profile;

Excel::import(new UsersImport, 'users.xlsx');

class UsersImport implements ToModel
{
    public function model(array $row)
    {
        return new User([
            'name' => $row[0],
            'email' => $row[1],
            'profile' => new Profile([
                'phone' => $row[2],
                'address' => $row[3],
            ]),
        ]);
    }
}

use Maatwebsite\Excel\Facades\Excel;
use App\User;
use App\Post;

Excel::import(new UsersImport, 'users.xlsx');

class UsersImport implements ToModel
{
    public function model(array $row)
    {
        $user = new User([
            'name' => $row[0],
            'email' => $row[1],
        ]);

        $user->posts()->create([
            'title' => $row[2],
            'content' => $row[3],
        ]);

        return $user;
    }
}

use Maatwebsite\Excel\Facades\Excel;
use App\User;
use App\Role;

Excel::import(new UsersImport, 'users.xlsx');

class UsersImport implements ToModel
{
    public function model(array $row)
    {
        $user = new User([
            'name' => $row[0],
            'email' => $row[1],
        ]);

        $user->roles()->attach(Role::where('name', $row[2])->first());

        return $user;
    }
}