def add_credit(self, price_tiering=True):
        self._add_credit_units(self.credit_units_per_game, price_tiering)
convert a neuron to JSON
dataset/ETHPy150Open missionpinball/mpf/mpf/modes/credits/code/credits.py/Credits.add_credit--crossover with--dataset/ETHPy150Open neurodata/ndstore/ocpca/jsonann.py/NeurontoJSON