toJson method
Implementation
@override
Map<String, dynamic> toJson() {
final json = super.toJson();
addWhenNotNull(json, "amount", amount.toString());
addWhenNotNull(json, "destination", destination);
addWhenNotNull(json, "settle_delay", settleDelay);
addWhenNotNull(json, "public_key", publicKey);
addWhenNotNull(json, "cancel_after", cancelAfter);
addWhenNotNull(json, "destination_tag", destinationTag);
return json;
}