Start composite tests
Another filtered test
Rename base class, comments
Move pre-update caching to just array list
Fix header imports to point to just protocol
Refactor of base class for easier enqueuing
rename base class
Add exception for unhandled type to base enqueue methods
Add description to notification wrappers
No need for separate sort descriptors when sorting
Move will/did change helpers to base class
Move observer logic to base class
Helper method in filtered list for confirming updates
Add second base class to separate notification caching from observer logic, for subclasses that don't need the former