I don't understand the reason that you want to add the scope functions as private. The scope is used to create a query, that will be done from outside of the class so that shouldn't be private.

Also the function shouldn't be static, see https://laravel.com/docs/5.6/eloquent#local-scopes for more information.

Sorry, It is necessary to define some methods to access scopeSample...

use Illuminate\Database\Eloquent\Model;

class Test extends Model {

    private static function scopeSample($query) {

        return $query->where('name');
    }

    public static function getTable() {
        $table = self::sample()
        ->get();

        return $table;
    }

     public static function getTableCount() {
        $table = self::sample()
        ->get();

        if ($table->count() === 0) {
            return false;
        }
        else
        {
            return true;
        }
    }
}

Actually I want to share the scope with different public methods.
I'm sorry for confusing you.

Because of the working of eloquent it isn't possible to set the scope functions on private.