* example, extensions type IDs specify what types to use for the corresponding values.
   *
   * If the hint is unknown [chooser] should return null which will cause the value to be decoded as
   * an opaque byte string.
   *
   * This may optionally wrap the contents in a tag.
   */
  fun usingTypeHint(chooser: (Any?) -> DerAdapter<*>?): DerAdapter<Any?> {