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

one use

	github.com/gotd/td/tg (current package)
		tl_upload_cdn_file_slices_gen.go#L57: func (s UploadCDNFileClassArray) Retain(keep func(x UploadCDNFileClass) bool) UploadCDNFileClassArray {