docs: def prepare(_next, self):
          """Hook after prepare and set expiration widget to
          ``self.form``.
          """
          _next(self)
          cfg = ugm_general(self.model)
          if cfg.attrs['users_account_expiration'] != 'True':
              return
          mode = 'edit'
          if not self.request.has_permission(
                  'manage_expiration', self.model.parent):
              mode = 'display'
          if self.action_resource == 'edit':
              attr = cfg.attrs['users_expires_attr']
              unit = int(cfg.attrs['users_expires_unit'])
              value = int(self.model.attrs.get(attr, 0))
              # if format days, convert to seconds
              if unit == 0:
                  value *= 86400
          else:
              value = UNSET
          expires_widget = factory(
              'field:label:expiration',
              name='active',
              value=value,
              props={
                  'label': _('active', default='Active')
              },
              mode=mode
          )
          save_widget = self.form['save']
          self.form.insertbefore(expires_widget, save_widget)