code: func FormatWrite(ctx formatter.Context, checkpoints []types.Checkpoint) error {
  	render := func(format func(subContext formatter.SubContext) error) error {
  		for _, checkpoint := range checkpoints {
  			if err := format(&checkpointContext{c: checkpoint}); err != nil {
  				return err
  			}
  		}
  		return nil
  	}
  	return ctx.Write(newCheckpointContext(), render)
  }
docs: // FormatWrite writes formatted checkpoints using the Context