ipyparallel and pymoo doesn't work

Hello all,
I am trying to use ipyparallel with a module for Genetic Algorithm (pymoo) and for that, I need to pass the class name 'MyProblem' to the clusters (don't know really why clusters are not aware but I have also the same problem with function defined in the main program). When I pass the name using 'dview["MyProblem"] = MyProblem' I am facing a recursing error.

This is the simplified code below which reproduce the error. Do you have any idea ?

```python
import numpy as np
import ipyparallel as ipp
from pymoo.algorithms.moo.nsga2 import NSGA2
from pymoo.core.problem import ElementwiseProblem
from pymoo.optimize import minimize

# Very simplified problem
class MyProblem(ElementwiseProblem):

def __init__(self):
super().__init__(n_var = 1,
n_obj = 1,
n_constr = 0,
xl=np.array([0]),
xu=np.array([1]))

def _evaluate(self, x, out, *args, **kwargs):

# Fitness functions (values to minimize)
f1 = -x[0]
out["F"] = [f1]

# Start the clusters
nb_core = 16
rc = ipp.Cluster(n=nb_core).start_and_connect_sync()
rc.wait_for_engines(n=nb_core)
dview = rc[:]

# Send class def to all cluster for further use
dview["MyProblem"] = MyProblem
```

Thanks in advance for your help.
Patrick.