interface Test

@Serializable
data class A(var aa: String) : Test

@Serializable
data class B(var bb: String) : Test

@Serializable
data class container(
        val test: Test
)

val container = container(
                A("a") //Ошибка - пишет что нет сериализатора
        )

val dd = dump(container)

@type

CxJsonElementType.BEGIN_OBJECT -> readObject {
      val nextKey = readNextKey(false)

      when {
      // string keyed map with first key escaped from keyword
        nextKey.startsWith("$") -> stringKeyedMap(readDynamicStringKeyedMapContents(nextKey.substring(1), linker))
      // reference, for example `{ "#class:field": "key value" }`
        nextKey.startsWith("#") -> entityReference(readDynamicReference(nextKey, linker))
      // keyword
        nextKey.startsWith("@") -> {
          val keyword = nextKey.substring(1)
          when (keyword) {
            "structure" -> {
              val valueType = readType(linker)
              structure(readJsonStructureContents(valueType as CxStructure<Any>, linker).instance)
            }
            "map" -> complexKeyedMap(readDynamicComplexKeyedMap(linker))
            "class" -> inlineEntity(readInlineEntityTypeAndContents<Any>(linker).instance)
            else -> error("unknown json @keyword: $nextKey, input: $this")
          }
        }
      // string keyed map
        else -> stringKeyedMap(readDynamicStringKeyedMapContents(nextKey, linker))
      }
    }