code: def test_random(self):
      from deepgraph._triu_indices import _triu_indices
  
      N = np.random.randint(900, 1100)
      n = N * (N - 1) / 2
      start = np.random.randint(0, n)
      end = np.random.randint(start, n)
  
      indices_true = np.triu_indices(N, k=1)
      sources_true = indices_true[0][start:end]
      targets_true = indices_true[1][start:end]
  
      indices_test = _triu_indices(N, start, end)
      sources_test = indices_test[0]
      targets_test = indices_test[1]
  
      assert (sources_true == sources_test).all() and (
          targets_true == targets_test
      ).all()
  
imports: import pytest
  import numpy
  import pandas
  from pandas.testing import assert_frame_equal
  from numpy.testing import assert_allclose
  from deepgraph import DeepGraph
label_desc: Use image node_id 1 for calling the TestTriuIndices obj's underlying member method code with example usage: obj.test_random() without return types