PropertyChangeEvent should not yield NULL on event,getValue() but does. Also, funny Jackson mappings are not documented.

[enver-haase]

When formManager.setValue(topicId, NULL) is called then the PropertyChangeHandler is called (if set), with the propertyChangeEvent.getValue() == NULL.

This may well simply be a documentation issue as

Object getValue()

is documented as 'not null'.

Please note that it is here where it should also be documented what the returned object may be.
In fact, getting a HashMap<String, Object> when e.g. some Java object was set as a value is more than surprising.
Can we add a link to a thorough documentation of how the serialization here works and the underlying mechanisms?
As self-made serialization/deserialization could be used within Jackson, we should point out we're actually using Jackson and what the consequences are.

https://vaadin.slack.com/archives/C01580Y9FLJ/p1728303879269009