code: public function send()
      {
          echo $this->content;
  
          if (function_exists('fastcgi_finish_request')) {
              fastcgi_finish_request();
          } elseif ('cli' !== php_sapi_name()) {
              $level = ob_get_level();
              if (0 < $level) {
                  $status = ob_get_status(true);
                  // PHP_OUTPUT_HANDLER_* are not defined on HHVM 3.3
                  $flags = defined('PHP_OUTPUT_HANDLER_REMOVABLE') ? PHP_OUTPUT_HANDLER_REMOVABLE | PHP_OUTPUT_HANDLER_FLUSHABLE : -1;
                  while ($level-- > 0 && ($s = $status[$level]) && (!isset($s['del']) ? !isset($s['flags']) || $flags === ($s['flags'] & $flags) : $s['del'])) {
                      ob_end_flush();
                  }
              }
          }
      }
docs: Send response.