def __call__(self, y, proba, sample_weight):
        raise NotImplementedError('To be derived by descendant')
converts a django/python datetime object to milliseconds since epoch
dataset/ETHPy150Open anaderi/lhcb_trigger_ml/hep_ml/metrics.py/AbstractMetric.__call__--crossover with--dataset/ETHPy150Open buildingenergy/buildingenergy-platform/seed/utils/time.py/convert_to_js_timestamp