class_docstr: Cast function.
class_docstr_tok: ["Cast","function","."]
code: def backward(self, indexes, g):
      if numpy.dtype(self._in_type).kind != "f":
          gx = None
      else:
          gx = cast(g[0], self._in_type)
      return (gx,)
  
file_path: chainer/chainer/functions/array/cast.py
imports: import numpy
  import chainer
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the Cast obj's underlying member method code with example usage: obj.backward(indexes, g) and returns: gx