code: def test_backprop_multiple_graphs_double_backprop(method0, method1):
      shape = (1,)
      dtype = chainerx.float32
  
      with chainerx.backprop_scope(
          "bp_x1"
      ) as bp_x1, chainerx.backprop_scope("bp_x0") as bp_x0:
          xs = (
              chainerx.full(shape, 2, dtype).require_grad(bp_x0),
              chainerx.full(shape, 3, dtype).require_grad(bp_x1),
          )
          expected_gxs = (
              None,
              chainerx.full(shape, 2, dtype),
          )
  
          def fprop(x0, x1):
              assert x0.is_grad_required(bp_x0)
  
              h = x0 * (x0 + x1)
              if method0 == "backward":
                  chainerx.backward(h, backprop_id=bp_x0)
                  gx0 = x0.get_grad(bp_x0)
              elif method0 == "grad":
                  (gx0,) = chainerx.grad([h], [x0], backprop_id=bp_x0)
              else:
                  assert False
  
              assert not gx0.is_backprop_required(bp_x0)
              assert gx0.is_backprop_required(bp_x1)
  
              return (x0 * gx0,)
  
          _check_backprop(
              method1, fprop, xs, expected_gxs, backprop_id=bp_x1
          )
  
imports: import chainerx
  import pytest
label_desc: Use image node_id 13 for calling a global function with example usage: test_backprop_multiple_graphs_double_backprop(method0, method1) and returns: unknown