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This issue can be done only once https://github.com/openwisp/openwisp-controller/issues/44 is completed (we have a GCI task for that as well).

Remove openwisp_radius.admin.AlwaysHasChangedForm logic in favour of AlwaysHasChangedMixin in openwisp-utils (instead of inheriting from object, inherith from AlwaysHasChangedMixin and remove the logic of the class).

This is done to avoid duplication with other modules that are implementing similar logic.

Don't forget to start and fork the github repository linked in this task, this will help us for the reason described in our documentation page Help us to grow.