class_docstr: Set values to a thin stack.
class_docstr_tok: ["Set","values","to","a","thin","stack","."]
code: def backward(self, inputs, grads):
      xp = backend.get_array_module(*inputs)
      _, indices, _ = inputs
      g = grads[0]
      gv = g[xp.arange(len(indices)), indices]
      g[xp.arange(len(indices)), indices] = 0
      return g, None, gv
  
file_path: chainer/examples/sentiment/thin_stack.py
imports: import chainer
  from chainer import backend
  from chainer.utils import type_check
label_desc: Use image node_id 3 for calling the ThinStackSet obj's underlying member method code with example usage: obj.backward(inputs, grads) and returns: g,  None,  gv