import React from 'react';
/**
 * Helper checks if value was passed through props and returns value from props or otherwise from state
 * @param {RadioValue | undefined} valueProp - value was passed through props
 * @param {RadioValue} valueState - value defined in state (by default value of first RadioButton)
 *
 * @returns {RadioValue} - value of RadioGroup
 */
export declare const getValue: (valueProp: string | number | undefined, valueState: string | number) => string | number;
/**
 * Helper checks if element is valid RadioButton
 * @param {React.ReactNode} element - Radio button element
 *
 * @returns {boolean} Is RadioButton element valid?
 */
export declare const isValidRadioButton: (element: React.ReactNode) => boolean;
/**
 * Helper gets value of the first component's child RadioButton
 * @param {React.ReactNode} children - child component's elements
 *
 * @returns {RadioValue} - value of the first child RadioButton
 */
export declare const getFirstChildValue: (children: React.ReactNode) => string | number;