XMLHttpRequest cannot load http://localhost:19200/socket.io/?EIO=3&transport=polling&t=LpASkye. The value of the 'Access-Control-Allow-Origin' header in the response must not be the wildcard '*' when the request's credentials mode is 'include'. Origin 'http://localhost:19000' is therefore not allowed access. The credentials mode of requests initiated by the XMLHttpRequest is controlled by the withCredentials attribute.
2.
decorators中不能用箭头函数