type io.WriterAt

8 uses

	io (current package)
		io.go#L249: type WriterAt interface {
		io.go#L571: 	w    WriterAt
		io.go#L578: func NewOffsetWriter(w WriterAt, off int64) *OffsetWriter {

	github.com/gotd/td/syncio
		writer_at.go#L12: 	w   io.WriterAt
		writer_at.go#L17: func NewWriterAt(w io.WriterAt) *WriterAt {

	github.com/gotd/td/telegram/downloader
		builder.go#L179: func (b *Builder) Parallel(ctx context.Context, output io.WriterAt) (_ tg.StorageFileTypeClass, err error) {
		parallel.go#L18: 	threads int, w io.WriterAt,
		sink.go#L10: func writeAtLoop(w io.WriterAt, toWrite <-chan block) func(context.Context) error {