code: def test_to_matrix_vector():
      mat, vec, xform = build_xform()
      newmat, newvec = to_matrix_vector(xform)
      np.testing.assert_array_equal(newmat, mat)
      np.testing.assert_array_equal(newvec, vec)
  
imports: import numpy
  from ..affine_utils import from_matrix_vector, to_matrix_vector
label_desc: Use image node_id 2 for calling a global function with example usage: test_to_matrix_vector() without return types