text: /**
   * Copyright 2018 Google 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.
   */
  
  goog.provide('impl');
  
  /**
   * @param {string} prefix
   * @constructor
   * @implements {iface}
   * @export
   * Exported in all versions so that we can check for renaming on the prototype.
   */
  impl = function(prefix) {
    /** @private {string} */
    this.prefix_ = prefix;
  };
  
  /**
   * @param {number} bar
   * @return {string}
   */
  impl.prototype.foo = function(bar) {
    return this.prefix_ + (bar * bar).toString();
  };
  