---
features:
  - Neutron's callback API found in ``neutron.callbacks.*`` is now exposed
    in ``neutron_lib.callbacks.*``. In addition, a set of event payload objects
    are now available for use in transporting event payload data in a
    standardized way.
  - A test fixture is provided for isolating the global callback manager in
    ``neutron_lib.callbacks.registry``. For more details see the comments in
    ``neutron_lib.fixture.CallbackRegistryFixture``.
deprecations:
  - The use of ``neutron_lib.callbacks.registry.notify()`` and
    ``neutron_lib.callbacks.manager.CallbacksManager.notify()`` is deprecated in
    favor of their ``publish()`` counterparts and will be removed in
    the "Queens" release time-frame.
