---
upgrade:
  - |
    OEM resource class hierarchy has been redesigned to allow for non-terminal
    sub-resources (e.g. Links) to be handled within OEM resource model. As a
    consequence, backward compatibility with previously existing OEM extension
    framework (anything based on ``OEMExtensionResourceBase`` class) is not
    preserved. User OEM code migration would involve switching from
    ``OEMExtensionResourceBase`` to ``OEMResourceBase`` (note ``__init__``
    call signature change) and replacing ``OEMField``-based classes with their
    generic sushy ``Field`` counterparts.
