/** {@inheritDoc} */
public Node mutate(Random rng, Probability mutationProbability, TreeFactory treeFactory) {
if (mutationProbability.nextEvent(rng)) {
return treeFactory.generateRandomCandidate(rng);
} else {
Node newLeft = left.mutate(rng, mutationProbability, treeFactory);
Node newRight = right.mutate(rng, mutationProbability, treeFactory);
if (newLeft != left && newRight != right) {
return newInstance(newLeft, newRight);
} else {
// Tree has not changed.
return this;
}
}
}
