class_docstr: Parametric Rectified Linear Unit gradient function.
code: def __init__(self, cond, reduce_axes, extended_shape):
      self.cond = cond
      self.reduce_axes = reduce_axes
      self.extended_shape = extended_shape
  
imports: import numpy
  import chainer
  from chainer.backends import cuda
  from chainer import function_node
  from chainer.utils import type_check
label_desc: Use image node_id 1 to create a new PReLUFunctionGrad object from inherited base classes: function_node with example: obj = PReLUFunctionGrad(cond, reduce_axes, extended_shape)