toJson method
Implementation
core.Map<core.String, core.dynamic> toJson() => {
if (firstPeriod != null) 'firstPeriod': firstPeriod!,
if (lastPeriod != null) 'lastPeriod': lastPeriod!,
if (periodType != null) 'periodType': periodType!,
if (price != null) 'price': price!,
if (priceTiers != null) 'priceTiers': priceTiers!,
};