toString method
A string representation of this object.
Some classes have a default textual representation,
often paired with a static parse function (like int.parse).
These classes will provide the textual representation as
their string representation.
Other classes have no meaningful textual representation
that a program will care about.
Such classes will typically override toString to provide
useful information when inspecting the object,
mainly for debugging or logging.
Implementation
@override
String toString() {
return '{"key": "$key", "amount": "$amount", "reason": "$reason", "phone": "$phone", "name": "$name", "email": "$email", "data": "$data", "partnerId": "$partnerId", "callback": "$callback", "apikey": "$apikey", "sandbox": "$sandbox", "theme": "$theme", "countries": "$countries", "paymentMethods": "$paymentMethods"}';
}