'Override (**mandatory**) to determine if an event took place in the last bar (bards[-1]).
:param instrument: Instrument identifier.
:type instrument: string.
:param bards: The BarDataSeries for the given instrument.
:type bards: :class:`pyalgotrade.dataseries.bards.BarDataSeries`.
:rtype: boolean.'

def eventOccurred(self, instrument, bards):

    raise NotImplementedError()
