local _M = {}

function _M.check_backend_args()
  local args = ngx.req.get_uri_args()
  for key, val in pairs(args) do
    if key == "backend" then
      val = tonumber(val)
      if val == nil then
        ngx.say("error: Wrong backend. Backends only supports numbers!")
      end
    end
  end
end

return _M