import io
import pickle
import espressomd
import espressomd.accumulators
import espressomd.observables
class ObsEncapsulator:
pass
obs = espressomd.observables.ParticlePositions(ids=[0,])
acc = espressomd.accumulators.MeanVarianceCalculator(obs=obs)
enc = ObsEncapsulator()
enc.obs = obs
buff = io.BytesIO()
out = pickle.Pickler(buff)
out.dump(obs)
out.dump(acc)
out.dump(enc)
buff.seek(0)
read = pickle.Unpickler(buff)
obs = read.load()
acc = read.load()
enc = read.load()
buff.close()
print(id(obs))
print(id(acc.get_params()['obs'])) # this is not a reference to 'obs' anymore
print(id(enc.obs)) # this is still a reference to 'obs'
