code: def _parse(self, node):
      if isinstance(node, tuple):
          # internal node
          if len(node) != 2:
              raise ValueError(
                  "All internal nodes must have two child nodes"
              )
          left, right = node
          self.path.append(self.next_id)
          self.next_id += 1
          self.code.append(1.0)
          self._parse(left)
  
          self.code[-1] = -1.0
          self._parse(right)
  
          self.path.pop()
          self.code.pop()
  
      else:
          # leaf node
          self.paths[node] = numpy.array(self.path, dtype=numpy.int32)
          self.codes[node] = numpy.array(self.code, dtype=self.dtype)
  
imports: import copy
  import numpy
  import six
  import chainer
  from chainer.backends import cuda
  from chainer import device_resident
  from chainer import function
  from chainer.initializers import uniform
  from chainer import link
  from chainer import utils
  from chainer.utils import type_check
  from chainer import variable
label_desc: Use image node_id 6 for calling the TreeParser obj's underlying member method code with example usage: obj._parse(node) without return types