title: DomCrawler. How to click button? "Unable to navigate from a "button" tag."
body: <p>I got form:</p>
  
  <pre><code>&lt;button type="submit" id="dostawa_zapisz" name="dostawa[zapisz]"&gt;Zapisz&lt;/button&gt;
  &lt;input type="hidden" id="dostawa__token" name="dostawa[_token]" value="foo"&gt;
  </code></pre>
  
  <p>and want to click it:</p>
  
  <pre><code>//        $link = $crawler-&gt;filter('button:contains("Zapisz")')-&gt;link();
  //        $link = $crawler-&gt;filterXPath('//*[@id="dostawa_zapisz"]')-&gt;link();
          $link = $crawler-&gt;selectButton('dostawa[zapisz]')-&gt;link();
          $crawler = $client-&gt;click($link);
  </code></pre>
  
  <p>but it show :</p>
  
  <blockquote>
    <p>"Unable to navigate from a "button" tag."</p>
  </blockquote>
  
  <p>(Is there any documentation about navigation using DomCrawler other than <a href="http://symfony.com/doc/current/components/dom_crawler.html" rel="nofollow">this</a>)</p>