TypeError: '_Broker' object is not callable

[sandeepbhutani304]

Expected Behavior

On optimize it should run smoothly as per documentation

Actual Behavior

Exception in thread Thread-1:
Traceback (most recent call last):
  File "C:\Users\sandeep\anaconda3\lib\threading.py", line 973, in _bootstrap_inner
    self.run()
  File "C:\Users\sandeep\anaconda3\lib\threading.py", line 910, in run
    self._target(*self._args, **self._kwargs)
  File "C:\sandcodes\backtest_realtime_f.py", line 2135, in bt_thread
    stats, heatmap = bt.optimize(
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1745, in optimize
    output = _optimize_grid()
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1635, in _optimize_grid
    _, values = Backtest._mp_task(backtest_uuid, batch_index)
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1755, in _mp_task
    return batch_index, [maximize_func(stats) if stats['# Trades'] else np.nan
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1755, in <listcomp>
    return batch_index, [maximize_func(stats) if stats['# Trades'] else np.nan
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1756, in <genexpr>
    for stats in (bt.run(**params)
  File "C:\sandcodes\backtesting_sand_f\backtesting.py", line 1245, in run
    broker: _Broker = self._broker(data=data)
TypeError: '_Broker' object is not callable
[]

Steps to Reproduce

        bt = None
        bt = Backtest(ticker, strat, #OpenLowIntraday, # OpenLow_SMA_Intraday,
                    cash=10000, commission=0.0003,
                    margin=1, #0.1, #best value as of now.. due to this trade count is changing
                    exclusive_orders=True, exclusive_orders_nocancel=True) # True)

        if OPTIMIZE_MODE == True:
            import numpy as np
            print("ENTERING OPTIMIZE MODE TO SEARCH BEST HYPER PARAMETERS::: ")
            stats, heatmap = bt.optimize(
                _pat_mul=range(1, 10),
                _macross_slope10threshold=list(np.arange(0.001, 1., 0.01)),
                _entry_price_factor=list(np.arange(1.0015, 1.01, 0.0001)),
                maximize='Equity Final [₹]',
                max_tries=200,
                random_state=0,
                return_heatmap=True,
                )

Additional info

• Backtesting version: 0.3.3
• bokeh.__version__:
• OS: Windows