def clear(self):
        self._results.clear()
        del self.results[:]
        self._dsk = {}
If a SELECT...FOR UPDATE NOWAIT is run on a database backend
dataset/ETHPy150Open dask/dask/dask/diagnostics/profile.py/Profiler.clear--crossover with--dataset/ETHPy150Open AppScale/appscale/AppServer/lib/django-1.5/tests/modeltests/select_for_update/tests.py/SelectForUpdateTests.test_unsupported_nowait_raises_error