code: def test_tril(self, xp, dtype):
      m = testing.shaped_arange(self.shape, xp, dtype)
      return xp.tril(m)
  
imports: import unittest
  import numpy
  import pytest
  import cupy
  from cupy import testing
label_desc: Use image node_id 1 for calling the TestTriLowerAndUpper obj's underlying member method code with example usage: obj.test_tril(xp, dtype) and returns: xp