text: /**
   * Copyright 2013-2015, Facebook, Inc.
   * All rights reserved.
   *
   * This source code is licensed under the BSD-style license found in the
   * LICENSE file in the root directory of this source tree. An additional grant
   * of patent rights can be found in the PATENTS file in the same directory.
   *
   * @providesModule memoizeStringOnly
   * @typechecks static-only
   */
  
  'use strict';
  
  /**
   * Memoizes the return value of a function that accepts one string argument.
   *
   * @param {function} callback
   * @return {function}
   */
  function memoizeStringOnly(callback) {
    var cache = {};
    return function (string) {
      if (!cache.hasOwnProperty(string)) {
        cache[string] = callback.call(this, string);
      }
      return cache[string];
    };
  }
  
  module.exports = memoizeStringOnly;