/**
 * Designed to be used in a loop to keep building a string
 * with `$glue` in-between.
 *
 * @param {string} $base - The string to append to.
 * @param {string} $append - The string that'll append to `$base`.
 * @param {string} $glue - The string used in between `$base` and `$append`.
 * @return {string}
 */
export declare function StringAppend($base: string, $append: string, $glue?: string): string;