code: def test_difference_matrix_broadcasting_cross() -> None:
      X = np.random.randn(2, 3, 4, 5)
      X2 = np.random.randn(8, 7, 6, 5)
      d = difference_matrix(X, X2)
      assert d.shape == (2, 3, 4, 8, 7, 6, 5)
  
file_path: GPflow/tests/gpflow/utilities/test_ops.py
imports: from typing import Union, cast
  import numpy
  import pytest
  import tensorflow
  from check_shapes import check_shapes
  import gpflow
  from gpflow.base import AnyNDArray
  from gpflow.utilities.ops import difference_matrix
label_desc: Use image node_id 4 for calling a global function with example usage: test_difference_matrix_broadcasting_cross() without return types