code: def test_cluster_map_size():
      nb_clusters = 11
      cluster_map = ClusterMap()
      clusters = [Cluster() for _ in range(nb_clusters)]
      cluster_map.add_cluster(*clusters)
  
      assert_equal(len(cluster_map), nb_clusters)
      assert_equal(cluster_map.size(), nb_clusters)
  
imports: import copy
  import itertools
  import numpy
  from numpy.testing import assert_array_equal, assert_raises, assert_equal
  from dipy.segment.clustering import Cluster, ClusterCentroid
  from dipy.segment.clustering import ClusterMap, ClusterMapCentroid
  from dipy.segment.clustering import Clustering
  from dipy.testing import assert_true, assert_false, assert_arrays_equal
  from dipy.testing.decorators import set_random_number_generator
label_desc: Use image node_id 17 for calling a global function with example usage: test_cluster_map_size() without return types