class_docstr: Flips an input variable in reverse order along the given axis.
code: def backward(self, indexes, grad_outputs):
      return (flip(grad_outputs[0], self.axis),)
  
file_path: chainer/chainer/functions/array/flip.py
imports: import six
  from chainer import backend
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 4 for calling the Flip obj's underlying member method code with example usage: obj.backward(indexes, grad_outputs) and returns: flip