title: Retrofit 2.0 beta1: how to post raw String body
body: <p>I am looking for some way to post request with raw body with new Retrofit 2.0b1. Something like this:</p>
  <pre><code>@POST(&quot;/token&quot;)
  Observable&lt;TokenResponse&gt; getToken(@Body String body);
  </code></pre>
  <p>As far as I understand, there should be some kind of strait &quot;to-string&quot; converter, but it is not clear to me yet how it works.</p>
  <p>There were ways to make it happen in 1.9 with TypedInput, but it does not help in 2.0 anymore.</p>