docs: def deactivate_user(self, user):
          """Deactivate a  user.
  
          :param user: A :class:`invenio_accounts.models.User` instance.
          :returns: The datastore instance.
          """
          res = super(SessionAwareSQLAlchemyUserDatastore, self).deactivate_user(
              user)
          if res:
              delete_user_sessions(user)
          return res