function getDefaultActiveKey(children) {
	  var defaultActiveKey = void 0;
	  _ValidComponentChildren2['default'].forEach(children, function (child) {
	    if (defaultActiveKey == null) {
	      defaultActiveKey = child.props.eventKey;
	    }
	  });

	  return defaultActiveKey;
	}
Unmount tabs (remove it from the DOM) when it is no longer visible