def track_metric(self, unique_identifier, metric, date, inc_amt=1, **kwargs):
        raise NotImplementedError()
Generates an unambiguous representation for instance and ordered dict.
dataset/ETHPy150Open numan/py-analytics/analytics/backends/base.py/BaseAnalyticsBackend.track_metric--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/google/appengine/api/search/search_util.py/Repr