code: def forward_gpu(self, inputs):
      self.retain_outputs((0,))
      (x,) = inputs
      out = cuda.cupyx.rsqrt(x, dtype=x.dtype)
      return (utils.force_array(out),)
  
imports: import numpy
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  from chainer import utils
  from chainer.utils import type_check
  import chainerx
label_desc: Use image node_id 3 for calling the RsqrtGPU obj's underlying member method code with example usage: obj.forward_gpu(inputs) and returns: utils