class_docstr: Select elements stored in given indices.
class_docstr_tok: ["Select","elements","stored","in","given","indices","."]
code: def backward(self, indexes, gy):
      t = self.get_retained_inputs()[0]
      ret = []
      if 0 in indexes:
          gx = Assign(self._in_shape, self._in_dtype, t).apply(gy)[0]
          ret.append(gx)
      if 1 in indexes:
          ret.append(None)
      return ret
  
file_path: chainer/chainer/functions/array/select_item.py
imports: import numpy
  import six
  import chainer
  from chainer import backend
  from chainer.backends import cuda
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 3 for calling the SelectItem obj's underlying member method code with example usage: obj.backward(indexes, gy) and returns: ret