code: def clf_centroids(self, clust, covmats, n_clusters):
      _, n_channels, n_channels = covmats.shape
      clf = clust(n_clusters=n_clusters).fit(covmats)
      centroids = clf.centroids()
      shape = (n_clusters, n_channels, n_channels)
      assert np.array(centroids).shape == shape
  
imports: from conftest import get_metrics
  import numpy
  from numpy.testing import assert_array_equal
  import pytest
  from pyriemann.clustering import Kmeans, KmeansPerClassTransform, Potato, PotatoField
label_desc: Use image node_id 3 for calling the TestRiemannianClustering obj's underlying member method code with example usage: obj.clf_centroids(clust, covmats, n_clusters) without return types