/**
 * Function provides a save string split functionality. If
 * the given string to split is undefined or null an empty
 * string array is returned.
 *
 * @param str string to split
 * @param separator separator of the split
 * @returns string []
 */
export declare function split(str?: string, separator?: string): string[];
/**
 * Function returns the number value of the given key, if
 * the key is not found the key is added and the current map
 * size is set as value.
 *
 * @param idMap Map with string key and number value
 * @param name string key
 * @returns number of the given key.
 */
export declare function getDigit(idMap: Map<string, number>, name: string): number;
export declare function getLetter(idMap: Map<string, number>, name: string): string;