/**
 * The base implementation of methods like `_.max` and `_.min` which accepts a
 * `comparator` to determine the extremum value.
 *
 * @private
 * @param {Array} array The array to iterate over.
 * @param {Function} iteratee The iteratee invoked per iteration.
 * @param {Function} comparator The comparator used to compare values.
 * @returns {*} Returns the extremum value.
 */
export default function baseExtremum<T>(array: T[], comparator: (v1: T, v2: T) => boolean): T;