def addon(options):
    """
    This function constructs a command line invocation that needs to be passed for invoking for a sub workflow.
    Only a certain subset of options are propogated to the sub workflow invocations if passed.
    """
    cmd_line_args = ""

    if options.recurse_mode:
        cmd_line_args += "--recurse "

    if options.quiet_mode:
        cmd_line_args += "--quiet "

    if options.summary_mode:
        cmd_line_args += "--summary "

    if options.use_files:
        cmd_line_args += "--files "

    new_indent = 1
    if options.indent_length is not None:
        new_indent = options.indent_length + 1

    cmd_line_args += "--indent " + str(new_indent) + " "

    return cmd_line_args