class_docstr: Nested dict-like object that proxies read and write operations through a root object.
  
  This lets us do synchronous serialization and lazy loading of large values.
class_docstr_tok: ["Nested","dict-like","object","that","proxies","read","and","write","operations","through","a","root","object",".","This","lets","us","do","synchronous","serialization","and","lazy","loading","of","large","values","."]
code: def __init__(self, root=None, path=()):
      self._path = tuple(path)
      if root is None:
          self._root = self
          self._json_dict = {}
      else:
          self._root = root
          json_dict = root._json_dict
          for k in path:
              json_dict = json_dict.get(k, {})
  
          self._json_dict = json_dict
      self._dict = {}
  
      # We use this to track which keys the user has set explicitly
      # so that we don't automatically overwrite them when we update
      # the summary from the history.
      self._locked_keys = set()
  
imports: import json
  import os
  import time
  from wandb_gql import gql
  import wandb
  from wandb import util
  from wandb.apis.internal import Api
  from wandb.sdk import lib
  from wandb.sdk.data_types.utils import val_to_json
label_desc: Use image node_id 1 to create a new SummarySubDict object  with example: obj = SummarySubDict(root, path)