docs: def remote_delete_user(model, request):
      """Remove user via remote service.
  
      Returns a JSON response containing success state and a message indicating
      what happened::
  
      {
          success: true, // respective false
          message: 'message'
      }
  
      Expected request parameters:
  
      id
          Id of user to delete.
      """
      params = request.params
      uid = params.get('id')
  
      if not uid:
          return {
              'success': False,
              'message': u"No user ID given.",
          }
  
      users = model.backend
      if uid not in users:
          return {
              'success': False,
              'message': u"User with given ID not exists.",
          }
  
      try:
          del users[uid]
          users.parent()
  
          message = u"Deleted user with ID '%s'." % uid
          return {
              'success': True,
              'message': message,
          }
      except Exception as e:
          return {
              'success': False,
              'message': str(e),
          }
      finally:
          model.invalidate()