code: public function merge(ValueBag $attributes, $override = false)
      {
          foreach ($attributes->all() as $key => $value) {
              if (!$this->has($key) || $override) {
                  $this->set($key, $value);
              }
          }
  
          return $this;
      }
docs: @param ValueBag $attributes
  @param bool     $override
  
  @return $this