/**
 * Given an indexed ICU string, condenses any select to an argument
 * Unindexed _gt_ source strings and indexed _gt_# translation strings
 * are mutually exclusive.
 * indexVars('Hello {_gt_1, select, other {World}}') => 'Hello {_gt_1}'
 * @param {string} icuString - The ICU string to condense.
 * @returns {string} The condensed ICU string.
 */
export declare function condenseVars(icuString: string): string;