title: Is there a way to set a base request parameter to be included in every request made with Square's Retrofit library?
body: <p>I'm using Square's Retrofit library for short-lived network calls. There are a few pieces of data that I include as <code>@Query</code> params on every request. Like so:</p>
  
  <pre><code>@GET("/thingOne.php")
  void thingOne(
          @Query("app_version") String appVersion,
          @Query("device_type") String deviceType,
          Callback&lt;Map&lt;String,Object&gt;&gt; callback
  );
  
  @GET("/thingTwo.php")
  void thingTwo(
          @Query("app_version") String appVersion,
          @Query("device_type") String deviceType,
          Callback&lt;Map&lt;String,Object&gt;&gt; callback
  );
  </code></pre>
  
  <p>It's cumbersome to have to define <code>appVersion</code> and <code>deviceType</code> for every single endpoint outlined in the <code>Interface</code>. Is there a way to set a base set of parameters that should be included with every request? Something similar to how we set a common <code>Authorization Header</code>?</p>
  
  <pre><code>RestAdapter restAdapter = new RestAdapter.Builder()
      .setServer("...")
      .setRequestHeaders(new RequestHeaders() {
          @Override
          public List&lt;Header&gt; get() {
              List&lt;Header&gt; headers = new ArrayList&lt;Header&gt;();
                  Header authHeader = new Header(
                      "Authorization", "Bearer " + token);
                  headers.add(authHeader);
              }
              return headers;
          }
      })
      .build();
  this.service = restAdapter.create(ClientInterface.class);
  </code></pre>