code: def _check_backprop(
      method, fprop, xs, expected_gxs, gys=None, backprop_id=None
  ):
      if method == "backward":
          check_func = _check_backward
      elif method == "grad":
          check_func = _check_grad
      else:
          assert False
  
      check_func(
          fprop, xs, expected_gxs, gys=gys, backprop_id=backprop_id
      )
  
imports: import chainerx
  import pytest
label_desc: Use image node_id 4 for calling a global function with example usage: _check_backprop(method, fprop, xs, expected_gxs, gys, backprop_id) without return types