decodeValue method Null safety

String decodeValue(
  1. String value
)

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));
}