code: def test_softplus_double_backward(seed, beta, ctx, func_name):
      from nbla_test_utils import (
          cap_ignore_region,
          backward_function_tester,
      )
  
      rng = np.random.RandomState(seed)
      inputs = [rng.randn(2, 3, 4).astype(np.float32) * 2]
      backward_function_tester(
          rng, F.softplus, inputs, func_args=[beta], ctx=ctx
      )
  
imports: import pytest
  import numpy
  import nnabla.functions
  from nbla_test_utils import list_context
label_desc: Use image node_id 3 for calling a global function with example usage: test_softplus_double_backward(seed, beta, ctx, func_name) without return types