code: def forward_gpu(self, inputs):
      gx = cuda.elementwise(
          "T gy, bool cond", "T gx", "gx = cond ? gy : T(0)", "clip_bwd"
      )(inputs[0], self.cond)
      return (gx,)
  
imports: import numpy
  from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the ClipGrad obj's underlying member method code with example usage: obj.forward_gpu(inputs) and returns: gx