/**
 * This is error exception type of {@link NumberReader }
 */
export declare class NotNumberError extends Error {
    constructor(wrongNumber?: string);
}
/**
 * Get number from {@link NumberMap} according to the input single number
 * @param number the input number, only 1 char is valid
 * @return string the number in string
 */
export declare function getNumberFromMap(number: string[1]): string;