old_contents: /**
   * Copyright 2014 Google Inc. All Rights Reserved.
   *
   * 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.
   */
  
  'use strict';
  
  if (!process.env.GCLOUD_TESTS_PROJECT_ID && !process.env.GCLOUD_TESTS_KEY) {
    var error = [
      'To run the system tests, you need to set some environment variables.',
      'Please check the Contributing guide for instructions.'
    ].join('\n');
    throw error;
  }
  
  module.exports = {
    keyFilename: process.env.GCLOUD_TESTS_KEY,
    projectId: process.env.GCLOUD_TESTS_PROJECT_ID
  };
  
new_contents: /**
   * Copyright 2014 Google Inc. All Rights Reserved.
   *
   * 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.
   */
  
  'use strict';
  
  var googleCloudConfig = {};
  
  if (!process.env.GCLOUD_TESTS_CREDENTIALS &&
      !process.env.GCLOUD_TESTS_PROJECT_ID &&
      !process.env.GCLOUD_TESTS_KEY) {
    throw new Error([
      'To run the system tests, you need to set some environment variables.',
      'Please check the Contributing guide for instructions.'
    ].join('\n'));
  }
  
  var credentials = process.env.GCLOUD_TESTS_CREDENTIALS;
  
  if (credentials) {
    googleCloudConfig.credentials = JSON.parse(credentials);
    googleCloudConfig.projectId = credentials.project_id;
  } else {
    googleCloudConfig.projectId = process.env.GCLOUD_TESTS_PROJECT_ID;
    googleCloudConfig.keyFilename = process.env.GCLOUD_TESTS_KEY;
  }
  
  module.exports = googleCloudConfig;
  
subject: add system test running capabilities (#1592)