Imports gitee.com/asktop_go/util/acast gitee.com/asktop_go/util/aclient gitee.com/asktop_go/util/afile gitee.com/asktop_go/util/aurl github.com/tencentyun/cos-go-sdk-v5 Standard library imports context errors io io/ioutil mime/multipart net/http net/url os path path/filepath strings