title: Mock adwords API
body: <p>I want to test my code that connects to the AdWords API, without making an actual call to Google (that costs money ;) ). Any idea how I can plug in a new implementation of TrafficEstimatorServiceInterface?</p>
  <p>AdWords Client API is using Guice for dependency injection, but I'm not sure how I can get the hold of the Injector in order to modify it?!</p>
  <p>If it helps, this is how I get the implementation of it now:</p>
  <pre class="lang-java prettyprint-override"><code>AdWordsServices adWordsServices = new AdWordsServices();
  AdWordsSession session = AdwordsUtils.getSession();
  
  TrafficEstimatorServiceInterface trafficEstimatorService =
      adWordsServices.get(session, TrafficEstimatorServiceInterface.class);
  </code></pre>