code: func (c *Controller) Auth(ctx *gin.Context) {
  	authHeader := ctx.GetHeader("Authorization")
  	if len(authHeader) == 0 {
  		httputil.NewError(ctx, http.StatusBadRequest, errors.New("please set Header Authorization"))
  		return
  	}
  	if authHeader != "admin" {
  		httputil.NewError(ctx, http.StatusUnauthorized, fmt.Errorf("this user isn't authorized to operation key=%s expected=admin", authHeader))
  		return
  	}
  	admin := model.Admin{
  		ID:   1,
  		Name: "admin",
  	}
  	ctx.JSON(http.StatusOK, admin)
  }
docs: // Auth godoc
  // @Summary Auth admin
  // @Description get admin info
  // @Tags accounts,admin
  // @Accept  json
  // @Produce  json
  // @Success 200 {object} model.Admin
  // @Failure 400 {object} httputil.HTTPError
  // @Failure 401 {object} httputil.HTTPError
  // @Failure 404 {object} httputil.HTTPError
  // @Failure 500 {object} httputil.HTTPError
  // @Security ApiKeyAuth
  // @Router /admin/auth [post]