github.com/gotd/td/tg.UploadCDNFileArray.Retain (method)

one use

	github.com/gotd/td/tg (current package)
		tl_upload_cdn_file_slices_gen.go#L247: func (s UploadCDNFileArray) Retain(keep func(x UploadCDNFile) bool) UploadCDNFileArray {