How to use the radian.settings.radian_settings function in radian

else:
                    print("unexpected error was caught.")
                    print("please report to https://github.com/randy3k/radian for such error.")
                    print(e)
                    import traceback
                    traceback.print_exc()
                    import os
                    os._exit(1)

            current_mode = session.current_mode

            if current_mode.on_post_accept:
                result = current_mode.on_post_accept(session)
                if result is not None:
                    return result
                if settings.insert_new_line and current_mode.insert_new_line:
                    app.output.write_raw("\n")
                text = None

        return text

activated = False
        for name in reversed(session.modes):
            mode = session.modes[name]
            if mode.activator and mode.activator(session):
                session.activate_mode(name)
                activated = True
                break
        if not activated:
            session.activate_mode("unknown")

        current_mode = session.current_mode

        if interrupted[0]:
            interrupted[0] = False
        elif not TERMINAL_CURSOR_AT_BEGINNING[0] or \
                (settings.insert_new_line and current_mode.insert_new_line):
            app.output.write_raw("\n")

        text = None

        while text is None:
            try:
                text = session.prompt(add_history=add_history)

            except KeyboardInterrupt:
                interrupted[0] = True
                raise

            except Exception as e:
                if isinstance(e, EOFError):
                    # todo: confirmation in "r" mode
                    return None

with suppress_stderr():
            try:
                token = rcompletion.assign_line_buffer(text_before)
                # do not timeout package::func
                if "::" in token or completion_requested:
                    timeout = 0
                else:
                    timeout = self.timeout
                rcompletion.complete_token(timeout)
                completions = rcompletion.retrieve_completions()
            except Exception:
                completions = []

        for c in completions:
            if c.startswith(token) and c != token:
                if c.endswith("=") and settings.completion_adding_spaces_around_equals:
                    c = c[:-1] + " = "
                if c.endswith("::"):
                    # let get_package_completions handles it
                    continue
                yield Completion(c, -len(token))

def newline(event, chars=["{", "[", "("]):
    should_indent = event.current_buffer.document.char_before_cursor in chars
    copy_margin = not in_paste_mode() and settings.auto_indentation
    event.current_buffer.newline(copy_margin=copy_margin)
    if should_indent and settings.auto_indentation:
        tab_size = settings.tab_size
        event.current_buffer.insert_text(" " * tab_size)

def auto_indentation():
    return settings.auto_indentation