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

one use

	github.com/gotd/td/tg (current package)
		tl_help_promo_data_slices_gen.go#L57: func (s HelpPromoDataClassArray) Retain(keep func(x HelpPromoDataClass) bool) HelpPromoDataClassArray {