code: function trapTabs(parentElement) {
  		if (parentElement.tabTrapInstalled)
  			return;
  		
  		parentElement.addEventListener("keydown", function (e) { //$NON-NLS-0$
  			if(e.keyCode === KEY.TAB) {
  				var first = firstTabbable(parentElement);
  				var last = lastTabbable(parentElement);
  				
  				if (first && last) {
  					if (e.target === last && !e.shiftKey) {
  						// wrap to first tabbable
  						first.focus();
  						stop(e);
  					}
  					else if (e.target === first && e.shiftKey) {
  						// wrap to last tabbable
  						last.focus();
  						stop(e);
  					}
  				}
  			} 
  		}, true);
  		parentElement.tabTrapInstalled = true;
  	}
docs: /* Trap the tabs within the given parent