@property
    def start(self):
        raise NotImplementedError("(%s).start" % self)
If rollback fails, L{ConnectionPool.runWithConnection} raises the
dataset/ETHPy150Open sympy/sympy/sympy/series/sequences.py/SeqBase.start--crossover with--dataset/ETHPy150Open kuri65536/python-for-android/python-modules/twisted/twisted/test/test_adbapi.py/ConnectionPoolTestCase.test_runWithConnectionRaiseOriginalError