text: /**
   * Copyright 2013 Facebook, Inc.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   *
   * @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)) {
        return cache[string];
      } else {
        return cache[string] = callback.call(this, string);
      }
    };
  }
  
  module.exports = memoizeStringOnly;
  