title: Angular2 BrowserDomAdapter ':eq(0)' selector giving an error
body: <p>I am converting my jQuery to Angular2 </p>
  
  <p>So I have such jQuery selector <code>$('.mdl-tabs__tab:eq(1)').addClass('active');</code> and it is working fine which analogue in Angular2 <code>dom.addClass(dom.query('.mdl-tabs__tab:eq(0)'), 'active');</code></p>
  
  <p>which is giving me an error:</p>
  
  <p><strong><em>ORIGINAL EXCEPTION: SyntaxError: Failed to execute 'querySelector' on 'Document': '.mdl-tabs__tab:eq(0)' is not a valid selector.</em></strong></p>
  
  <p>any thought why and how to fix?</p>