code: def node(self, left, right):
      return F.tanh(self.l(F.concat((left, right))))
  
imports: import argparse
  import warnings
  import numpy
  import chainer
  import chainer.functions
  import chainer.links
  from chainer import reporter
  from chainer import training
  from chainer.training import extensions
  import data
  import thin_stack
label_desc: Use image node_id 3 for calling the ThinStackRecursiveNet obj's underlying member method code with example usage: obj.node(left, right) and returns: F