What does `n_dim` mean?

[lesshaste]

In the example at https://github.com/microprediction/humpday/blob/main/black_box_optimization_package_recommender.ipynb there is n_dim=4. However the defined function my_objective has only dimension 2. What does it mean when n_dim is larger than the number of dimensions in the argument for the objective function?

[microprediction]

Ignores vars 3 and 4

[newbie-lad]

So, what is the use of it then. Can it be set automatically even.
[is it bad to ignore unused parameters]