validate method
void
validate()
Implementation
void validate() {
if (format != qrFormat) {
throw const FormatException('QR format must be "qr".');
}
_qrValue(rawValue);
_qrValueType(valueType);
if (!scannedAtUtc.isUtc) {
throw const FormatException('QR scannedAtUtc must be UTC.');
}
}