ResourceManager

class MyResourceHolder(
  private val manager: LifecycleBoundResources = ResourceManager()
): LifecycleBoundResources by manager, AutoCloseable by manager {
  // ...
  private fun somethingThatSpawnsAResource() {
    val resource = // ...
    register(resource)
  }
}

// later ...
val instance = MyResourceHolder()
instance.use {
  // the inner resource will be closed automatically
}