code: func TsvPrintf(writer io.Writer, reader io.Reader, format string) error {
  	return TakeTsv(reader, -1, func(args []string) error {
  		var objects []interface{}
  		for _, arg := range args {
  			objects = append(objects, arg)
  		}
  		if len(objects) > 0 {
  			_, err := fmt.Fprintf(writer, format, objects...)
  			return err
  		}
  		return nil
  	})
  }
docs: // TsvPrintf reads TSV lines from reader,
  // and formats according to a format specifier and writes to writer.