docs: def save_user(self, request, sociallogin, form=None):
          """
          Saves a newly signed up social login. In case of auto-signup,
          the signup form is not available.
          """
          u = sociallogin.user
          u.set_unusable_password()
          if form:
              get_account_adapter().save_user(request, u, form)
          else:
              get_account_adapter().populate_username(request, u)
          sociallogin.save(request)
          return u