def _maybe_convert_sort_keys(table, exprs):
    try:
        return [to_sort_key(table, k) for k in util.promote_list(exprs)]
    except com.IbisError:
        return None
def _maybe_convert_sort_keys(table, exprs):
    try:
        return [to_sort_key(table, k) for k in util.promote_list(exprs)]
    except com.IbisError:
        return None