title: Setting a tag to a Retrofit Call in order to cancel by tag later
body: <p>I am using a Retrofit service interface that generates my Call objects, very much like the example one they show:</p>
  
  <pre><code>public interface GitHubService {
      @GET("users/{user}/repos")
      Call&lt;List&lt;Repo&gt;&gt; listRepos(@Path("user") String user);
  }
  </code></pre>
  
  <p>I would like to be able to cancel all Call objects generated by the listRepos method that have been enqueued or are running. I see that I can add a tag to the Call object's Request builder, but how can I swap the Request on a Call? It does not seem like I can modify the Request of a Call after it has already been created.</p>