How to use the finmarketpy.backtest.BacktestRequest function in finmarketpy

# for logging
    from findatapy.util import LoggerManager

    # for signal generation
    from finmarketpy.economics import TechIndicator, TechParams

    # for plotting
    from chartpy import Chart, Style

    logger = LoggerManager().getLogger(__name__)

    import datetime

    backtest = Backtest()
    br = BacktestRequest()
    fxconv = FXConv()

    # get all asset data
    br.start_date = "02 Jan 1990"
    br.finish_date = datetime.datetime.utcnow()
    br.spot_tc_bp = 2.5  # 2.5 bps bid/ask spread
    br.ann_factor = 252

    tech_params = TechParams();
    tech_params.sma_period = 200;
    indicator = 'SMA'
    tech_params.only_allow_longs = True
    # tech_params.only_allow_shorts = True

    # pick EUR/USD
    # note: we are calculating returns from spot (it is much better to use to total return

# for logging
    from findatapy.util.loggermanager import LoggerManager

    # for signal generation
    from finmarketpy.economics import TechIndicator, TechParams

    # for plotting
    from chartpy import Chart, Style

    logger = LoggerManager().getLogger(__name__)

    import datetime

    backtest = Backtest()
    br = BacktestRequest()
    fxconv = FXConv()

    # get all asset data
    br.start_date = "02 Jan 1990"
    br.finish_date = datetime.datetime.utcnow()
    br.spot_tc_bp = 2.5  # 2.5 bps bid/ask spread
    br.ann_factor = 252

    # have vol target for each signal
    br.signal_vol_adjust = True
    br.signal_vol_target = 0.05
    br.signal_vol_max_leverage = 3
    br.signal_vol_periods = 60
    br.signal_vol_obs_in_year = 252
    br.signal_vol_rebalance_freq = 'BM'
    br.signal_vol_resample_freq = None

def load_parameters(self, br = None):
        if br is not None: return br

        ##### FILL IN WITH YOUR OWN BACKTESTING PARAMETERS
        br = BacktestRequest()

        # get all asset data
        br.start_date = "04 Jan 1989"
        br.finish_date = datetime.datetime.utcnow().date()
        br.spot_tc_bp = 0.5
        br.ann_factor = 252

        br.plot_start = "01 Apr 2015"
        br.calc_stats = True
        br.write_csv = False
        br.plot_interim = True
        br.include_benchmark = True

        # have vol target for each signal
        br.signal_vol_adjust = True
        br.signal_vol_target = 0.1

def load_parameters(self, br = None):

        if br is not None: return br

        ##### FILL IN WITH YOUR OWN BACKTESTING PARAMETERS
        br = BacktestRequest()

        # get all asset data
        br.start_date = "04 Jan 1989"
        br.finish_date = datetime.datetime.utcnow().date()
        br.spot_tc_bp = 0.5
        br.ann_factor = 252

        br.plot_start = "01 Apr 2015"
        br.calc_stats = True
        br.write_csv = False
        br.plot_interim = True
        br.include_benchmark = True

        # have vol target for each signal
        br.signal_vol_adjust = True
        br.signal_vol_target = 0.1