public function rules(): array 	{ 		return [ 			'discount_code' => ['nullable', 'string', 'max:10'], 			'country_code' => ['required', 'string', 'size:2'],  			'items' => ['required', 'array'], 			'items.*.id' => ['required', 'uuid', 'distinct', 'exists:products,id'], 			'items.*.quantity' => ['required', 'integer', 'min:1'], 			'is_vat' => ['boolean'],  			'email' => ['required', 'email', 'max:50'], 			'phone_number' => ['required', 'string', 'max:20'], 			'language' => ['required', 'string', 'size:2', new Enum(Language::class)], 			'name' => ['required', 'string', 'max:50'], 			'surname' => ['required', 'string', 'max:50'], 			'company_name' => ['nullable', 'string', 'max:20'], 			'vat_number' => ['nullable', 'string', 'max:30'],  			'delivery_address' => ['required', 'string', 'max:50'], 			'delivery_zip_code' => ['required', 'string', 'max:20'], 			'delivery_city' => ['required', 'string', 'max:50'], 			'delivery_country' => ['required', 'string', 'max:30'],  			'billable_address' => ['nullable', 'string', 'max:50'], 			'billable_zip_code' => ['nullable', 'string', 'max:20'], 			'billable_city' => ['nullable', 'string', 'max:50'], 			'billable_country' => ['nullable', 'string', 'max:30'],  			'delivery_company_name' => ['nullable', 'string', 'max:100'], 		]; 	}