code: def test_fit_two_clusters(self, estimator, dataset, expected):
      if gs.unique(expected).shape[0] > 2:
          raise ValueError("Expected only two clusters")
  
      estimator.fit(dataset)
  
      clustering_labels = estimator.labels_
      self.assertAllEqual(clustering_labels, expected)
  
imports: import geomstats.backend
  from geomstats.test.test_case import TestCase
label_desc: Use image node_id 1 for calling the AgglomerativeHierarchicalClusteringTestCase obj's underlying member method code with example usage: obj.test_fit_two_clusters(estimator, dataset, expected) without return types