code: func WithVersion(version string) Opt {
  	return func(c *Client) error {
  		if version != "" {
  			c.version = version
  			c.manualOverride = true
  		}
  		return nil
  	}
  }
docs: // WithVersion overrides the client version with the specified one. If an empty
  // version is specified, the value will be ignored to allow version negotiation.