Custom deserialization of null values

[achimmihca]

I found that null values do not call custom deserializations. Instead, the value is just set to null.

This prevents custom deserialization of null values. For example, one cannot replace null with an empty string or empty list.

My use case is that I have JSON settings wrapped in observable properties, namely in an UniRx.ReactiveProperty.
Now, I'd like to deserialize a null value by settings the ReactiveProperty's value to null.
But what happens instead is that the ReactiveProperty itself is set to null, which leads to null pointer exceptions and subsribers not being notified.

Is there a way to handle null values in custom deserialization?