How to use the xalpha.universal.cachedio function in xalpha

def test_ioconf_keyfunc():
    get_daily_key = xa.universal.cachedio(
        path="./", backend="csv", key_func=lambda s: s[::-1]
    )(xa.universal._get_daily)
    df1 = get_daily_key("BA", start="2020-03-03")
    get_daily_key = xa.universal.cachedio(path="./", backend="csv")(
        xa.universal._get_daily
    )
    df2 = get_daily_key("AB", fetchonly=True)
    assert df2.iloc[-1]["close"] == df1.iloc[-1]["close"]

def test_cache_io():
    get_daily_csv = xa.universal.cachedio(path="./", prefix="pytestl-", backend="csv")(
        xa.universal._get_daily
    )
    df = get_daily_csv("SH501018", start="2020-01-24", end="2020/02/02")
    assert len(df) == 0
    df = get_daily_csv("SH501018", start="2020-01-23", end="20200203")
    assert len(df) == 2
    df = get_daily_csv("SH501018", start="2020-01-24", end="20200205")
    assert len(df) == 3
    df = get_daily_csv("SH501018", start="2020-01-23")
    df = get_daily_csv("SH501018")
    df = get_daily_csv("SH501018", end="2020-02-01")
    assert df.iloc[0]["date"].strftime("%Y%m%d") == "20190201"
    xa.universal.check_cache("SH501018", prev=32, omit_lines=1)

def test_ioconf_keyfunc():
    get_daily_key = xa.universal.cachedio(
        path="./", backend="csv", key_func=lambda s: s[::-1]
    )(xa.universal._get_daily)
    df1 = get_daily_key("BA", start="2020-03-03")
    get_daily_key = xa.universal.cachedio(path="./", backend="csv")(
        xa.universal._get_daily
    )
    df2 = get_daily_key("AB", fetchonly=True)
    assert df2.iloc[-1]["close"] == df1.iloc[-1]["close"]