+var opt_line_id_prefix = new OptionString("Prefix of the id of each line <span> element", "--line-id-prefix")
+var opt_first_line = new OptionInt("Start the source file at this line (default: 1)", 0, "--first-line")
+var opt_last_line = new OptionInt("End the source file at this line (default: to the end)", 0, "--last-line")