Fetches and renders current user's settings.

def Handle(self, unused_args, token=None):
    """Fetches and renders current user's settings."""

    result = ApiGrrUser(username=token.username)

    if data_store.RelationalDBEnabled():
      user_record = data_store.REL_DB.ReadGRRUser(token.username)
      result.InitFromDatabaseObject(user_record)
    else:
      try:
        user_record = aff4.FACTORY.Open(
            aff4.ROOT_URN.Add("users").Add(token.username),
            aff4_users.GRRUser,
            token=token)

        result.InitFromAff4Object(user_record)
      except IOError:
        result.settings = aff4_users.GRRUser.SchemaCls.GUI_SETTINGS()

    result.interface_traits = (
        self.interface_traits or ApiGrrUserInterfaceTraits())

    return result