Passing number of centroids unused

In update koan there is

    pub fn compute_centroids(
        n_centroids: usize,
        // (n_observations, n_features)
        observations: &ArrayBase<impl Data<Elem = f64>, Ix2>,
        // (n_observations,)
        cluster_memberships: &ArrayBase<impl Data<Elem = usize>, Ix1>,
    ) -> Array2<f64> {

but here the n_centroids is not being used for anything in the solution, and thus it doesn't seem necessary. Maybe there is a bug here?

Open src/koans/06_update/02_centroids_array2.rs and inspect compute_centroids, focusing on whether n_centroids is needed for the intended centroid calculation. Compare the function signature with the surrounding koan and determine whether the argument should affect the result or be removed; the issue is done when that behavior is resolved consistently.