code: def test_kmeans2_empty(self):
      # Regression test for gh-1032.
      assert_raises(ValueError, kmeans2, [], 2)
  
imports: from __future__ import division, print_function, absolute_import
  import warnings
  import sys
  import numpy
  from numpy.testing import assert_array_equal, assert_array_almost_equal, assert_allclose, assert_equal, assert_
  from scipy._lib._numpy_compat import suppress_warnings
  import pytest
  from pytest import raises
  from scipy.cluster.vq import kmeans, kmeans2, py_vq, vq, whiten, ClusterError, _krandinit
  from scipy.cluster import _vq
  from scipy.sparse.sputils import matrix
label_desc: Use image node_id 10 for calling the TestKMean obj's underlying member method code with example usage: obj.test_kmeans2_empty() without return types