类UsersTableSeeders不存在[ReflectionException]

pra*_*rel 4 php laravel-5.4

    <?php
use Illuminate\Database\Seeder;
use App\User;

class UsersTableSeeders extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
       User::create([
                'name'=>'prakash',
                'username'=>'prakash',
                'email'=>'rockpokhrel@gmail.com',
                'password'=> bycrypt('pokhrel'),
                'remember_token'=> str_random(10),
            ]);
    }
}
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我不明白为什么我收到此错误:[ReflectionException]类UsersTableSeeders不存在

Aar*_*rez 7

composer dump-autoload在终端上尝试命令.