) {
        when {
          isOptional && value == optionalValue -> {
            // Write nothing.
          }

          else -> {
            for ((type, adapter) in choices) {
              if (type.isInstance(value) || (value == null && type == Unit::class)) {
                (adapter as DerAdapter<Any?>).toDer(writer, value)
                return
              }
            }
          }
        }