def convert(self, value, param, ctx):
        try:
            currencies = value.split('_')
            assert len(currencies) == 2
            return Instrument(currencies[0], currencies[1])
        except (__HOLE__, ValueError):
            self.fail('{} is not a valid instrument'.format(value), param, ctx)
dataset/ETHPy150Open jmelett/pyFxTrader/trader/instruments.py/InstrumentParamType.convert