def _evolve_kwargs(self):
        """Filter None keyword arguments. Intended to be passed on to algorithm.evolve(...)"""
        valid_evolve_kwargs = (
            'max_generations', 'max_evaluations', 'pop_size', 'neighborhood_size', 'tournament_size', 'mutation_rate')
        filtered_evolve_kwargs = dict()
        for key in valid_evolve_kwargs:
            attr_value = getattr(self, key)
            if attr_value is not None:
                filtered_evolve_kwargs[key] = attr_value
        # return filtered_evolve_kwargs
        return {}
Filter None keyword arguments. Intended to be passed on to algorithm.evolve(...)