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

one use

	github.com/gotd/td/tg (current package)
		tl_page_block_slices_gen.go#L982: func (s PageBlockPreformattedArray) Retain(keep func(x PageBlockPreformatted) bool) PageBlockPreformattedArray {