/**
 * If the provided className is a string, it will be returned as is.
 * Otherwise, the function will call the className function with the ownerState as the first argument.
 *
 * @param className
 * @param ownerState
 */
export declare function resolveClassName<OwnerState>(className: string | ((state: OwnerState) => string) | undefined, ownerState: OwnerState): string | undefined;