I get below errors while running backtesting, please can you confirm if source code is correct



class RollingMax(IndicatorBase[IndicatorDataPoint]):
    def __init__(self, name: str, period: int):
        super().__init__(name)
        self._period = period
        self._window = RollingWindow[float](period)

    @property
    def IsReady(self) -> bool:
        return self._window.IsReady

    def ComputeNextValue(self, input: IndicatorDataPoint) -> float:
        if self._window.Count == self._period:
            self._window.RemoveAt(self._period - 1)
        self._window.Add(input.Value)
        return float(max(self._window)) if self._window.Count > 0 else float('nan')

Errors

Runtime Error: cannot instantiate abstract class
  at __init__
    self.max_close = RollingMax(f"{symbol.Value}_MAXC{cfg.n_breakout}", cfg.n_breakout)
                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 in state.py: line 12
  at OnSecuritiesChanged
    st = SymbolState(self, sym, self.cfg)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 in main.py: line 62