code: public function visitDocumentationBlock(DocumentationBlock $documentationBlock)
      {
          $this->typeCheck->visitDocumentationBlock(func_get_args());
  
          $parameters = array();
          $paramTags = $documentationBlock->tagsByName('param');
          $lastIndex = count($paramTags) - 1;
          $variableLength = false;
          foreach ($paramTags as $index => $paramTag) {
              $parameters[] = $paramTag->accept($this);
              if ($index === $lastIndex) {
                  $variableLength = preg_match(
                      static::PATTERN_VARIABLE_LENGTH,
                      $paramTag->content()
                  ) && true;
              }
          }
  
          return new ParameterList($parameters, $variableLength);
      }
docs: @param DocumentationBlock $documentationBlock
  
  @return ParameterList