text: import numpy as np
  from numpy.testing import *
  
  from supreme.resolve.ordering import *
  import scipy.sparse as sparse
  
  def test_basic():
      A = sparse.csr_matrix([[0, 1, 0, 2],
                             [2, 0, 1, 1],
                             [0, 0, 0, 1],
                             [0, 0, 1, 0],
                             [0, 0, 0, 0]])
  
      P = standard_form(A)
  
      PA = P * A
  
      assert_array_equal(PA.todense(), [[0, 0, 0, 0],
                                        [2, 0, 1, 1],
                                        [0, 1, 0, 2],
                                        [0, 0, 1, 0],
                                        [0, 0, 0, 1]])
  