@abc.abstractmethod
    def get_metering_label(self, context, label_id, fields=None):
        pass
Return either a string, JSON-encoding dict()s as necessary
dataset/ETHPy150Open openstack/neutron/neutron/extensions/metering.py/MeteringPluginBase.get_metering_label--crossover with--dataset/ETHPy150Open matthiask/plata/plata/fields.py/JSONField._flatten_value