decodeValue method
Implementation
String decodeValue(String value) {
assert(value.isNotEmpty);
final encoderKey = value.substring(0, 1);
if (!encoderMap.containsKey(encoderKey)) {
throw ArgumentError('No encoder to match the $encoderKey');
}
final encoder = encoderMap[encoderKey]!;
return encoder.decode(value.substring(1));
}