@abstractproperty
    def instance_hash(self):
        pass
wasSuccessful() becomes False after errors have been reported.
dataset/ETHPy150Open quantopian/zipline/zipline/sources/data_source.py/DataSource.instance_hash--crossover with--dataset/ETHPy150Open twisted/twisted/twisted/trial/test/test_reporter.py/ReporterInterfaceTests.test_wasSuccessfulFalseAfterErrors