Issue while deserializing

[sukesh2000]

Hey folks,
I've a kotlin data classes like this:

data class Config{
    val stub: StubConfiguration = StubConfiguration(),
    val attributeSelectionPattern: AttributeSelectionPattern = AttributeSelectionPattern()
}

data class StubConfiguration(
    val generative: Boolean? = false,
    val delayInMilliseconds: Long? = getLongValue(STUB_DELAY), // reads from environment variable
    val dictionary: String? = getStringValue(STUB_DICTIONARY), // reads from environment variable
    val includeMandatoryAndRequestedKeysInResponse: Boolean? = null
)

data class AttributeSelectionPattern(
    @field:JsonAlias("default_fields")
    val defaultFields: List<String> = readEnvVarOrProperty(
        ATTRIBUTE_SELECTION_DEFAULT_FIELDS,
        ATTRIBUTE_SELECTION_DEFAULT_FIELDS
    ).orEmpty().split(",").filter { it.isNotBlank() }, // reads from environment variable
    @field:JsonAlias("query_param_key")
    val queryParamKey: String = readEnvVarOrProperty(
        ATTRIBUTE_SELECTION_QUERY_PARAM_KEY,
        ATTRIBUTE_SELECTION_QUERY_PARAM_KEY
    ).orEmpty() // reads from environment variable
)

Now when I serialize the Config class using

val config = Config()
val objectMapper = ObjectMapper(YAMLFactory()).apply {
    registerKotlinModule()
    setSerializationInclusion(JsonInclude.Include.NON_DEFAULT)
}

objectMapper.writeValueAsString(config)

I get this in the YAML

stub: {}
attributeSelectionPattern: {}

And I don't want these fields to be present in my output YAML if there isn't any data, are there any flags present which can skip these kind of empty keys?

I've tried combination of adding flags like JsonInclude.Include.NON_EMPTY, JsonInclude.Include.NON_NULL, JsonInclude.Include.NON_ABSENT, JsonInclude.Include.NON_DEFAULT on top of Config class and individual data classes but none of it seems to be working. Kindly help.