code: def _update_user_roles_names_from_roles_id(self, user, users_roles,
                                                 roles_list):
          
          user_roles_names = [role.name for role in roles_list
                              if role.id in users_roles]
          current_user_roles_names = set(getattr(user, "roles", []))
          user.roles = list(current_user_roles_names.union(user_roles_names))
docs: Add roles names to user.roles, based on users_roles.
  
          :param user: user to update
          :param users_roles: list of roles ID
          :param roles_list: list of roles obtained with keystone