title: problem with multiple HTTP requests in Laravel with Guzzle
body: <p>I'm using Guzzle version 6.3.3. I want to make multiple HTTP requests from an external API. The code shown below worker perfect for me. This is just one single request.</p>
  
  <pre><code>public function getAllTeams()
  {
      $client = new Client();
      $uri = 'https://api.football-data.org/v2/competitions/2003/teams';
      $header = ['headers' =&gt; ['X-Auth-Token' =&gt; 'MyKey']];
      $res = $client-&gt;get($uri, $header);
      $data = json_decode($res-&gt;getBody()-&gt;getContents(), true);
      return $data['teams'];
  }
  </code></pre>
  
  <p>But now I want to make multiple requests at once. In the documentation of Guzzle I found out how to do it, but it still didn't work properly. This is the code I try to use.</p>
  
  <pre><code>    $header = ['headers' =&gt; ['X-Auth-Token' =&gt; 'MyKey']];
      $client = new Client(['debug' =&gt; true]);
      $res = $client-&gt;send(array(
          $client-&gt;get('https://api.football-data.org/v2/teams/666', $header),
          $client-&gt;get('https://api.football-data.org/v2/teams/1920', $header),
          $client-&gt;get('https://api.football-data.org/v2/teams/6806', $header)
      ));
      $data = json_decode($res-&gt;getBody()-&gt;getContents(), true);
      return $data;
  </code></pre>
  
  <p>I get the error:</p>
  
  <blockquote>
    <p><code>Argument 1 passed to GuzzleHttp\Client::send() must implement interface Psr\Http\Message\RequestInterface, array given called in TeamsController.</code></p>
  </blockquote>
  
  <p>If I remove the <code>$header</code> after each URI then I get this error:</p>
  
  <blockquote>
    <p><code>resulted in a '403 Forbidden' response: {"message": "The resource you are looking for is restricted. Please pass a valid API token and check your subscription fo (truncated...)</code></p>
  </blockquote>
  
  <p>I tried several ways to set <code>X-Auth-Token</code> with my API key. But I still get errors and I don't know many other ways with Guzzle to set them.</p>
  
  <p>I hope someone can help me out :)</p>