<filename>pymoo/operators/mutation/nom.py
from pymoo.core.mutation import Mutation


class NoMutation(Mutation):

    def _do(self, problem, X, **kwargs):
        return X

<filename>pymoo/operators/mutation/nom.py
from pymoo.core.mutation import Mutation


class NoMutation(Mutation):

    def _do(self, problem, X, **kwargs):
        return X
