code: func (p *UserPrivileges) ActiveRoles(ctx sessionctx.Context, roleList []*auth.RoleIdentity) (bool, string) {
  	mysqlPrivilege := p.Handle.Get()
  	u := p.user
  	h := p.host
  	for _, r := range roleList {
  		ok := mysqlPrivilege.FindRole(u, h, r)
  		if !ok {
  			logutil.Logger(context.Background()).Error("find role failed", zap.Stringer("role", r))
  			return false, r.String()
  		}
  	}
  	ctx.GetSessionVars().ActiveRoles = roleList
  	return true, ""
  }
docs: // ActiveRoles implements privilege.Manager ActiveRoles interface.