How to use the technical.history.__init__.OHLCV.session.merge function in technical

# calculate the difference in days and download and merge the data files

        for row in historical_data(stake, asset, interval, latest_time, ccxt_api):
            o = OHLCV(
                id="{}-{}-{}/{}:{}".format(ccxt_api.name, interval, asset.upper(), stake.upper(), row[0]),
                exchange=ccxt_api.name,
                pair="{}/{}".format(asset.upper(), stake.upper()),
                interval=interval,
                open=row[1],
                close=row[4],
                high=row[2],
                low=row[3],
                volume=row[5],
                timestamp=row[0]
            )
            OHLCV.session.merge(o)

    # return all data to user
    result = []

    # filter by exchange, currency and other pairs
    for row in OHLCV.session.query(OHLCV).filter(
            OHLCV.exchange == ccxt_api.name,
            OHLCV.pair == "{}/{}".format(asset.upper(), stake.upper()),
            OHLCV.interval == interval,
            OHLCV.timestamp >= from_date * 1000,
            OHLCV.timestamp <= till_date * 1000,
    ).all():
        result.append([row.timestamp, row.open, row.high, row.low, row.close, row.volume])

    return result

# store data for all
        for row in historical_data(stake, asset, interval, from_date, ccxt_api):
            o = OHLCV(
                id="{}-{}-{}/{}:{}".format(ccxt_api.name, interval, asset.upper(), stake.upper(), row[0]),
                exchange=ccxt_api.name,
                pair="{}/{}".format(asset.upper(), stake.upper()),
                interval=interval,
                open=row[1],
                close=row[4],
                high=row[2],
                low=row[3],
                volume=row[5],
                timestamp=row[0]
            )
            OHLCV.session.merge(o)

    else:
        # calculate the difference in days and download and merge the data files

        for row in historical_data(stake, asset, interval, latest_time, ccxt_api):
            o = OHLCV(
                id="{}-{}-{}/{}:{}".format(ccxt_api.name, interval, asset.upper(), stake.upper(), row[0]),
                exchange=ccxt_api.name,
                pair="{}/{}".format(asset.upper(), stake.upper()),
                interval=interval,
                open=row[1],
                close=row[4],
                high=row[2],
                low=row[3],
                volume=row[5],
                timestamp=row[0]