def _slice(self, view):
        if self._data is not None:
            return self._data[view]
        return self._proxy.get_view(self.id, view)
An errback added with DeferredContext.addCallbacks has its result passed
dataset/ETHPy150Open ejeschke/ginga/ginga/RemoteImage.py/RemoteImage._slice--crossover with--dataset/ETHPy150Open ClusterHQ/eliot/eliot/tests/test_twisted.py/DeferredContextTests.test_addCallbacksErrbackResult