class_docstr: Example taken from Chainer docs:
  
  See: https://docs.chainer.org/en/stable/guides/functions.html
code: def forward_cpu(self, inputs):
      x, y, z = inputs
      w = x * y + z
      return (w,)
  
file_path: chainerrl/chainerrl/functions/mul_add.py
imports: import chainer
  from chainer import cuda
label_desc: Use image node_id 1 for calling the MulAdd obj's underlying member method code with example usage: obj.forward_cpu(inputs) and returns: w