title: CssSelector for compound class fails to work, what can be the reason?
body: <p>On www.parcelhero.com I'm trying to capture the following 
  Webelement:</p>
  
  <pre><code>&lt;div class="bs-container btn-group bootstrap-select show-tick show-menu-arrow open" style="top: 315.2px; left: 241px; width: 179px;"&gt;
  </code></pre>
  
  <p>using</p>
  
  <pre><code>driver.findElement(By.cssSelector("bs-container.btn-group.bootstrap-select.show-tick.show-menu-arrow.open"));
  </code></pre>
  
  <p>But I'm getting </p>
  
  <blockquote>
    <p>"no such element: Unable to locate element: {"method":"css
    selector","selector":"bs-container.btn-group.bootstrap-select.show-tick.show-menu-arrow.open"}"</p>
  </blockquote>
  
  <p>But if I use</p>
  
  <pre><code>driver.findElement(By.xpath("//div[@class='bs-container btn-group bootstrap-select show-tick show-menu-arrow open']"))
  </code></pre>
  
  <p>It works. Why?</p>