class ModelToMultiPartBodyBuilder {

    fun provide(any: Any) =
        MultipartBody.Builder().apply {
            fromMap(any.toMap())

        }

    private fun MultipartBody.Builder.fromMap(map: Map<String, Any?>) {
        map
            .forEach { entry ->
                when (entry.value) {
                    is List<*> -> {
                        (entry.value as List<*>).forEachIndexed { index, any ->
                            any?.toMap()?.let {
                                fromMap(
                                    it.asIterable()
                                        .associate { newEntry -> "${entry.key}[$index].${newEntry.key}" to newEntry.value }
                                )
                            }
                        }
                    }
                    else -> addFormDataPart(entry.key, entry.value.toString())
                }
            }
    }

    private fun Any.toMap(): Map<String, Any?> =
        Gson().run {
            fromJson(toJson(this@toMap), object : TypeToken<Map<String, Any?>>() {}.type)
        }
}