code: public List<WnsNotificationResponse> pushBadge(List<String> channelUris, WnsBadge badge) throws WnsException {
  		return this.pushBadge(channelUris, null, badge);
  	}
docs: Pushes a badge to channelUris
  @param channelUris
  @param badge which should be built with {@link ar.com.fernandospr.wns.model.builders.WnsBadgeBuilder}
  @return list of WnsNotificationResponse for each channelUri, please see response headers from <a href="http://msdn.microsoft.com/en-us/library/windows/apps/hh465435.aspx#send_notification_response">http://msdn.microsoft.com/en-us/library/windows/apps/hh465435.aspx#send_notification_response</a>
  @throws WnsException when authentication fails