static.go
func GenerateETag(fileSize, fileName, modTime string) string {
	etag := fileSize + fileName + modTime
	return base64.StdEncoding.EncodeToString([]byte(etag))
}
func GenerateETag(fileSize, fileName, modTime string) string {
	etag := fileSize + fileName + modTime
	return base64.StdEncoding.EncodeToString([]byte(etag))
}
func GenerateETag ( fileSize , fileName , modTime string ) string { etag := fileSize + fileName + modTime return base64 . StdEncoding . EncodeToString ( [ ] byte ( etag ) ) }
// GenerateETag generates an ETag based on size, filename and file modification time
GenerateETag generates an ETag based on size filename and file modification time