为什么需要Any作为类型绑定

Question

为什么类型参数T在下面（取自https://gist.github.com/quangIO/a623b5caa53c703e252d858f7a806919）需要Any的界线？

private class Json<out T : Any>(private val klass: Class<T>, private val jsonMapper: ObjectMapper) : ColumnType() {

    override fun valueFromDB(value: Any): Any {
        value as PGobject
        return try {
            jsonMapper.readValue(value.value, klass)
        } catch (e: Exception) {
            e.printStackTrace()
            throw RuntimeException("Can't parse JSON: $value")
        }
    }
}