export interface OptionGroupUnstyledClasses {
    root: string;
    label: string;
    list: string;
}
export type OptionGroupUnstyledClassKey = keyof OptionGroupUnstyledClasses;
export declare function getOptionGroupUnstyledUtilityClass(slot: string): string;
declare const optionGroupUnstyledClasses: OptionGroupUnstyledClasses;
export default optionGroupUnstyledClasses;