`shouldExpandNode` is only calculated on mount vs. update

[gnestor]

Example (notice how logs are only printed to the console after a nested node is unmounted and re-mounted, that is when shouldExpandNode is called):

I'm trying to implement a filter for the data JSON tree so that users can easily navigate to leaf nodes, but shouldExpandNode is only calculated in the constructor of JSONNestedNode, so when the data in JSONTree changes, shouldExpandNode doesn't update unless a JSONNestedNode is unmounted and re-mounted.