title: Guzzle6 error Invalid resource type: array when send a GuzzleHttp\Psr7\Request
body: <p>I am trying to send a code by using GuzzleHttp\Psr7\Request,somehow I get error  Invalid resource type: array, the following is my codes</p>
  
  <pre><code>$params = ["name"=&gt;"myName","id"=&gt;"myId"];
  $client = new Client();
  $request = new Request('PUT','https://api.hitbox.tv/media/live/myName?authToken=myToken',["content-type"=&gt;'application/json'],["json"=&gt;$params]);
  
  $response = $client-&gt;send($request);
  </code></pre>
  
  <p>I'm following <a href="https://stackoverflow.com/a/36492389/6516422">this</a> guide.</p>