public function rules(): array 	{ 		return [ 			'up_to_2_kg' => ['required', 'integer', 'min:0'], 			'up_to_5_kg' => ['required', 'integer', 'min:0'], 			'up_to_10_kg' => ['required', 'integer', 'min:0'], 			'up_to_15_kg' => ['required', 'integer', 'min:0'], 			'up_to_20_kg' => ['required', 'integer', 'min:0'], 			'up_to_25_kg' => ['required', 'integer', 'min:0'], 			'up_to_32_kg' => ['required', 'integer', 'min:0'], 			'islands_extra' => ['nullable', 'integer', 'min:0'], 			'additional_costs' => ['required', 'integer', 'min:0'], 		]; 	}