:param tmpl: Template content string or file
    :param at_paths: Template search paths

def render_impl(**kwargs):
    """
    :param tmpl: Template content string or file
    :param at_paths: Template search paths
    """
    if Template is None:
        tmpl = kwargs.get("file", None)
        if tmpl is None:
            tmpl = kwargs.get("source", None)
            return anytemplate.engines.base.fallback_renders(tmpl)

        return anytemplate.engines.base.fallback_render(tmpl, None, **kwargs)

    return Template(**kwargs).respond()