code: public function read(string $name, $default = null)
      {
          $val = $this->primary->read($name, $this);
  
          if ($val === $this) {
              $val = $this->secondary->read($name, $default);
  
              if ($this->autoSync) {
                  $this->primary->write($name, $val);
              }
          }
  
          return $val;
      }
docs: {@inheritdoc}