title: Retrofit with QueryMap
body: <p>I have some request with the same <strong>endpoint</strong> but parameter and return type are different. </p>
  
  <p>I used <code>@QueryMap</code> for the parameter but I don't know how to write the return type: </p>
  
  <p>Must I write:</p>
  
  <pre><code>@GET("xxx")
  Call&lt;List&lt;A1&gt;&gt; groupList1(@QueryMap Map&lt;String, String&gt; options);
  @GET("xxx")
  Call&lt;List&lt;A2&gt;&gt; groupList2(@QueryMap Map&lt;String, String&gt; options);
  @GET("xxx")
  Call&lt;List&lt;A3&gt;&gt; groupList3(@QueryMap Map&lt;String, String&gt; options);
  ....
  </code></pre>
  
  <p>or there is a shorter solution?</p>