Add unit tests for config

**Feature request**
It would be great to have serialization for types.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_serialization` with default `false`.

Start by locating the config handling and any existing unit tests in the repository. Read how configuration options are defined and consumed, then determine the expected serialization behavior and verify that enable_serialization defaults to false and is covered by tests.

Written by the indexing model from the issue text.