def get_template_i18n(template_name, locale):
    """Build template list with preceding locale if found."""
    if locale is None:
        return [template_name]

    template_list = []
    parts = template_name.rsplit(".", 1)
    root = parts[0]
    suffix = parts[1]

    if locale.territory is not None:
        locale_string = "_".join([locale.language, locale.territory])
        localized_template_path = ".".join([root, locale_string, suffix])
        template_list.append(localized_template_path)

    localized_template_path = ".".join([root, locale.language, suffix])
    template_list.append(localized_template_path)

    # append the default
    template_list.append(template_name)
    return template_list
Build template list with preceding locale if found.