toJson method

Implementation

JsonMap toJson() => {
  if (deviceCode != null) 'device_code': deviceCode,
  if (userCode != null) 'user_code': userCode,
  if (expiresIn != null) 'expires_in': expiresIn,
  if (interval != null) 'interval': interval,
  if (verificationUrl != null) 'verification_url': verificationUrl,
};