expired method
Implementation
String expired({DateTime? expiresIn}) {
if (expiresIn != null && DateTime.now().isBefore(expiresIn)) {
throw FormatException('expiresIn should be a past date');
}
// expired at one hour
final expiration = expiresIn != null
? dateToSeconds(expiresIn)
: dateToSeconds(DateTime.now()) - 3600;
final header = _generateHeader();
final payload = _generatePayload({
'iat': dateToSeconds(DateTime.now()),
'exp': expiration,
});
final signature = _generateSignature(header, payload);
return '$header.$payload.$signature';
}