'Returns the InstrumentSubplot for a given instrument
:rtype: :class:`InstrumentSubplot`.'

def getInstrumentSubplot(self, instrument):

    try:
        ret = self.__barSubplots[instrument]
    except KeyError:
        ret = InstrumentSubplot(instrument, self.__plotBuySell)
        self.__barSubplots[instrument] = ret
    return ret
