code: def test_dtype(self):
      out = array([[1, 0, 0], [1, 1, 0], [1, 1, 1]])
      assert_array_equal(tri(3), out)
      assert_array_equal(tri(3, dtype=bool), out.astype(bool))
  
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 1 for calling the TestTri obj's underlying member method code with example usage: obj.test_dtype() without return types