@Serializable
        class FloatLong(val float: Float = .0f, val long: Long = 0L)

        object FloatLongSerializer : KSerializer<FloatLong> {
            override val descriptor: SerialDescriptor = SerialDescriptor("FloatLong", UnionKind.CONTEXTUAL)
            override fun deserialize(decoder: Decoder): FloatLong { TODO() }
            override fun serialize(encoder: Encoder, value: FloatLong) {
                val output = encoder as? JsonOutput ?: throw SerializationException("This class can be saved only by Json")
                val j = output.json.toJson(
                    JsonElementSerializer.list,
                    listOf<JsonElement>(
                        JsonPrimitive(value.float),
                        JsonPrimitive(value.long)
                    )
                )
                output.encodeJson(j)
            }
        }