title: RESTeasy - how to set Response field using @Context annotation
body: <p>Using RESTeasy 3.0.12, the code</p>
  
  <pre><code>@Context
  private org.jboss.resteasy.spi.HttpResponse response;
  </code></pre>
  
  <p>doesn't work. Response is always null.</p>
  
  <p>How to configure RESTeasy to enable the injection via @Context?</p>
  
  <p>-- 
  The code is pretty straightforward:
  IF:</p>
  
  <pre><code>@Path("api/v1/admin")
  @Produces("application/json")
  @Consumes("application/json")
  public interface AdminService
  {
  
      @PUT
      @Path("resource/{id}")
      ServiceResponse&lt;Resource&gt; updateResource(@PathParam("id") long ....
  </code></pre>
  
  <p>impl:</p>
  
  <pre><code>public class AdminServiceImpl implements AdminService
  {
  
      @Context
      private HttpServletResponse httpServletResponse; // &lt;== instance always null
  
      @Override
      public ServiceResponse&lt;Resource&gt; updateResource(long resourceId, ...
  </code></pre>