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define(['./isSymbol'], function(isSymbol) {
  /** Used as a safe reference for `undefined` in pre-ES5 environments. */  var undefined;
  /**   * 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.   */  function baseExtremum(array, iteratee, comparator) {    var index = -1,        length = array.length;
    while (++index < length) {      var value = array[index],          current = iteratee(value);
      if (current != null && (computed === undefined            ? (current === current && !isSymbol(current))            : comparator(current, computed)          )) {        var computed = current,            result = value;      }    }    return result;  }
  return baseExtremum;});