public function rules(): array 	{ 		return [ 			'title' => ['required', 'string', 'max:100'], 			'period_from' => ['nullable', 'date', 'required_with:period_to'], 			'period_to' => ['nullable', 'date', 'after:period_from'], 			'is_percentage' => ['boolean'], 			'amount' => ['required', 'numeric', 'min:0'], 			'active' => ['boolean'], 		]; 	}