Simulator.data object sometimes empty after simulation.

[e2crawfo]

Found and explained by @adityagilra in #12. Here is the relevant text:

In simulator.py line 185, I had to modify it to check if data is not empty:

            if len(data)>0:
                if data[0].shape != true_shape:
                    data = map(
                        partial(np.reshape, newshape=true_shape), data)

I was calling sim.run() multiple times in my code and on some calls, data would be empty.

I tried reproducing this in a separate small test script, but couldn't. I thought this might be if the 'sample_every' param for a probe is larger than the 'duration' in the sim.run(duration), then data might be zero length. But this worked fine in the test script. So am unsure why this happens in my script.