code: def test_correct_backward_unary():
      _check_backward_unary(lambda xs: (xs[0] * xs[0],))
  
file_path: chainer/tests/chainerx_tests/unit_tests/test_check_backward.py
imports: import pytest
  import chainerx
label_desc: Use image node_id 2 for calling a global function with example usage: test_correct_backward_unary() without return types