code: public function getNamedParams(string $category = null) : array
      {
          switch($category)
          {
              case 'attribute':
                  return $this->request->getAttributes();
  
              case 'query':
                  return $this->request->getQueryParams();
  
              case 'uploaded_files':
                  return $this->request->getUploadedFiles();
  
              case 'parsed_body':
                  {
                      $body = $this->request->getParsedBody();
                      if (!$body){
                          return [];
                      }
                      if (is_array($body)){
                          return $body;
                      }
                      if (is_object($body)){
                          return get_object_vars($body);
                      }
                  }
                  return [];
  
              case 'server':
                  return $this->request->getServerParams();
  
              case 'cookie':
                  return $this->request->getCookieParams();
          }
          return [];
      }
docs: Return named parameters
  
  @param string $category
  
  @return array