Replace the pretty printing code [here](https://github.com/choderalab/integrator-benchmark/blob/master/benchmark/serialization/serialize_integrators.py) with use of [`PrettyPrintableIntegrator`](https://github.com/choderalab/openmmtools/blob/fix-zerostep-case/openmmtools/integrators.py#L59-L122)
Replace the pretty printing code here with use of
PrettyPrintableIntegrator