serialize method

Implementation

@override
Map<String, String> serialize() {
  final Map<String, String> jsonMap = super.serialize();
  final List<Map<String, String>> jsonConditions =
      conditions.map((SerializableWaitCondition condition) {
        return condition.serialize();
      }).toList();
  jsonMap['conditions'] = json.encode(jsonConditions);
  return jsonMap;
}