code: def _check_backward_unary(fprop):
      x = chainerx.array([1, 2, 1], chainerx.float32)
      x.require_grad()
  
      chainerx.check_backward(
          fprop,
          (x,),
          (chainerx.array([0, -2, 1], chainerx.float32),),
          (chainerx.full((3,), 1e-3, chainerx.float32),),
      )
  
file_path: chainer/tests/chainerx_tests/unit_tests/test_check_backward.py
imports: import pytest
  import chainerx
label_desc: Use image node_id 1 for calling a global function with example usage: _check_backward_unary(fprop) without return types