Possibility to migrate changes on save method?

[jorekai]

Hey is it possible to migrate changes in custom save methods of a document?
I could not determine this by reading through the docs. Below is a small example

before changes:

class Test(Document):
  fieldA = ...
  fieldB = ...

after changes:

class Test(Document):
  fieldA = ...
  fieldB = ...
  fieldC = ...
  
  def save(self, *args, **kwargs):
    do_sth_with_fieldC()
    super().save()