@classmethod
    def get_label(cls, config):
        label = getattr(cls, config.label_var)
        return label
Build a map of <device_id> => <balance> where <balance> is a float
dataset/ETHPy150Open espeed/bulbs/bulbs/model.py/Relationship.get_label--crossover with--dataset/ETHPy150Open openstack/swift/swift/common/ring/builder.py/RingBuilder._build_balance_per_dev