code: def test_bad_length(self, x_len, y_len):
      x, y = np.ones(x_len), np.ones(y_len)
      with pytest.raises(
          ValueError, match="x and y must have the same length."
      ):
          histogram2d(x, y)
  
imports: from numpy.testing import assert_equal, assert_array_equal, assert_array_max_ulp, assert_array_almost_equal, assert_raises, assert_
  from numpy import arange, add, fliplr, flipud, zeros, ones, eye, array, diag, histogram2d, tri, mask_indices, triu_indices, triu_indices_from, tril_indices, tril_indices_from, vander
  import numpy
  import pytest
label_desc: Use image node_id 8 for calling the TestHistogram2d obj's underlying member method code with example usage: obj.test_bad_length(x_len, y_len) without return types