code: def testSoftplusGradNegInf(self):
      check_grads(
          nn.softplus,
          (-float("inf"),),
          order=1,
          rtol=1e-2 if jtu.test_device_matches(["tpu"]) else None,
      )
  
imports: import collections
  from functools import partial
  import itertools
  import unittest
  from absl.testing import absltest
  from absl.testing import parameterized
  import scipy.stats
  from jax._src import config
  from jax._src import core
  from jax._src import test_util
  from jax._src import ad_checkpoint
  from jax.test_util import check_grads
  from jax import nn
  from jax import random
  import jax
  import jax.numpy
label_desc: Use image node_id 4 for calling the NNFunctionsTest obj's underlying member method code with example usage: obj.testSoftplusGradNegInf() without return types