title: how to post string as byte[] using retrofit
body: <p>I need to post my query string as byte[] with retrofit 2; how can I do this? is any converter for this purpose ?
  when I use this code : </p>
  
  <pre><code>Call&lt;ResponseBody&gt; login(@Body byte[] body);
  </code></pre>
  
  <p>I get this error :</p>
  
  <pre><code>Unable to create @Body converter for byte[]
  </code></pre>