code: def initialize_root(self):
      self.parents = []
  
file_path: autograd/autograd/misc/tracers.py
imports: from itertools import repeat
  from autograd.wrap_util import wraps
  from autograd.util import subvals, toposort
  from autograd.tracer import trace, Node
  from functools import partial
label_desc: Use image node_id 2 for calling the ConstGraphNode obj's underlying member method code with example usage: obj.initialize_root() without return types