Class 'Model' not found

assalamualaiku teman teman , error ini terjadi ketika saya membuat seeder yang bernama PostCommentSeeder.php

 <?php

use Illuminate\Database\Seeder;

class PostCommentSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        $content='lorem ipsum bla bla bla';
        for ($i=1; $i <=20; $i++) {
        	$post = new Post;
        	$post->title = "Post no $i";
        	$post->read_more = substr($content, 0, 120);
        	$post->content = $content;
        	$post->save();

        	$maxComments = mt_rand(3,15);
        	for ($j=1; $j <= $maxComments; $j++) {
        		$comment = new Comment;
        		$comment->commenter = 'xyz';
        		$comment->comment = substr($content, 0,120);
        		$comment->email = 'xyz@xmail.com';
        		$post->comments()->save($comment);
        		$post->increment('comment_count');
        	}
        }
    }
}

dan UserTableSeeder.php

 <?php

use Illuminate\Database\Seeder;

class UserTableSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        //Uncomment the below to wipe the table clean before populating
        DB::table('users')->truncate();
        $user = array('name' =>'Administrator' ,
        			'email'	=> 'admin@admin.com',
        			'password'=> 'Hash::make('admin')',
        			'created_at'=> 'DB::raw('NOW()')',
        			'updated_at'=> 'DB::raw('NOW()')',
        );

        //comment the below to stop the seeder
        DB::table('users')->insert($user);
    }
}

dan ini DatabaseSeeder.php

 <?php

use Illuminate\Database\Seeder;

class DatabaseSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
    	Model::unguard();
    	$this->call([PostCommentSeeder::class,
    				UserTableSeeder::class,
    	]);
    }
}

masalahnya adalah ketika saya jalankan perintah composer dump-autoload tidak ada error

 PS D:\xampp\htdocs\blog> composer dump-autoload
Generating optimized autoload files
> Illuminate\Foundation\ComposerScripts::postAutoloadDump
> @php artisan package:discover
Discovered Package: fideloper/proxy
Discovered Package: laravel/tinker
Package manifest generated successfully.

akan tetapi ketika saya ketikkan command php artisan db:seed keluar error nya

PS D:\xampp\htdocs\blog> php artisan db:seed

In DatabaseSeeder.php line 14:

  Class 'Model' not found