original_string: public function normalizeId($id)
      {
          if (!\is_string($id)) {
              $id = (string) $id;
          }
          if (isset($this->normalizedIds[$normalizedId = strtolower($id)])) {
              $normalizedId = $this->normalizedIds[$normalizedId];
              if ($id !== $normalizedId) {
                  @trigger_error(sprintf('Service identifiers will be made case sensitive in Symfony 4.0. Using "%s" instead of "%s" is deprecated since Symfony 3.3.', $id, $normalizedId), E_USER_DEPRECATED);
              }
          } else {
              $normalizedId = $this->normalizedIds[$normalizedId] = $id;
          }
  
          return $normalizedId;
      }
code: public function normalizeId($id)
      {
          if (!\is_string($id)) {
              $id = (string) $id;
          }
          if (isset($this->normalizedIds[$normalizedId = strtolower($id)])) {
              $normalizedId = $this->normalizedIds[$normalizedId];
              if ($id !== $normalizedId) {
                  @trigger_error(sprintf('Service identifiers will be made case sensitive in Symfony 4.0. Using "%s" instead of "%s" is deprecated since Symfony 3.3.', $id, $normalizedId), E_USER_DEPRECATED);
              }
          } else {
              $normalizedId = $this->normalizedIds[$normalizedId] = $id;
          }
  
          return $normalizedId;
      }
code_tokens: public function normalizeId ( $ id ) { if ( ! \ is_string ( $ id ) ) { $ id = ( string ) $ id ; } if ( isset ( $ this -> normalizedIds [ $ normalizedId = strtolower ( $ id ) ] ) ) { $ normalizedId = $ this -> normalizedIds [ $ normalizedId ] ; if ( $ id !== $ normalizedId ) { @ trigger_error ( sprintf ( 'Service identifiers will be made case sensitive in Symfony 4.0. Using "%s" instead of "%s" is deprecated since Symfony 3.3.' , $ id , $ normalizedId ) , E_USER_DEPRECATED ) ; } } else { $ normalizedId = $ this -> normalizedIds [ $ normalizedId ] = $ id ; } return $ normalizedId ; }
docstring: Returns the case sensitive id used at registration time.
  
  @param string $id
  
  @return string
  
  @internal
docstring_tokens: Returns the case sensitive id used at registration time .