code: public function render($sBadgeMessage, array $aBadgeAttributes = null)
      {
          if (!is_scalar($sBadgeMessage)) {
              throw new InvalidArgumentException(sprintf(
                  'Badge message expects a scalar value, "%s" given',
                  is_object($sBadgeMessage) ? get_class($sBadgeMessage) : gettype($sBadgeMessage)
              ));
          }
  
          if (empty($aBadgeAttributes)) {
              $aBadgeAttributes = array('class' => 'badge');
          } else {
              if (empty($aBadgeAttributes['class'])) {
                  $aBadgeAttributes['class'] = 'badge';
              } elseif (!preg_match('/(\s|^)badge(\s|$)/', $aBadgeAttributes['class'])) {
                  $aBadgeAttributes['class'] .= ' badge';
              }
          }
  
          if (null !== ($oTranslator = $this->getTranslator())) {
              $sBadgeMessage = $oTranslator->translate($sBadgeMessage, $this->getTranslatorTextDomain());
          }
  
          return sprintf(
              static::$badgeFormat,
              $this->createAttributesString($aBadgeAttributes),
              $sBadgeMessage
          );
      }
docs: Retrieve badge markup
  @param string $sBadgeMessage
  @param  array $aBadgeAttributes : [optionnal]
  @throws InvalidArgumentException
  @return string