title: Getting JSON from RetrofitError object using Retrofit
body: <p>I am using the Retrofit library to do REST calls to a service I am using.  </p>
  
  <p>If I make an API call to my service and have a failure, the service returns a bit of JSON along with the standard HTTP error stuff.  Using the <code>RetrofitError</code> object included in the failure callback I am able to find the HTTP status code and several other things, however I am not able to retrieve the JSON that the service sends back.</p>
  
  <p>For example, let's say I make a call to the API where I am trying to create a user.  If the username already exists the service will return a 400 error code along with some JSON like this:</p>
  
  <pre><code>{"error":"Username already in use"}
  </code></pre>
  
  <p>Because a simple 400 error code isn't specific enough I really need access to the JSON that is returned.  </p>
  
  <p>Does anyone know how I can get at this JSON data? I have tried looking at every field in the <code>RetrofitError</code> object and can't find it anywhere.  Is there something additional I need to be doing?</p>