public function rules(): array 	{ 		return [ 			'lang' => ['nullable', 'string', new Enum(DomainLanguages::class)], 			'code' => ['required', 'string', Rule::exists(Applicant::class)->where(function ($query) { 				return $query->whereRaw('BINARY `code` = ?', [$this->code]) 					->where('is_offline', false) 					->where('filled', false); 			})], 		]; 	}