123456789101112131415161718192021222324252627282930
define(['./toString'], function(toString) {
  /** Used to generate unique IDs. */  var idCounter = 0;
  /**   * Generates a unique ID. If `prefix` is given, the ID is appended to it.   *   * @static   * @since 0.1.0   * @memberOf _   * @category Util   * @param {string} [prefix=''] The value to prefix the ID with.   * @returns {string} Returns the unique ID.   * @example   *   * _.uniqueId('contact_');   * // => 'contact_104'   *   * _.uniqueId();   * // => '105'   */  function uniqueId(prefix) {    var id = ++idCounter;    return toString(prefix) + id;  }
  return uniqueId;});