class_docstr: Helper class to build experiments or trials graph.
class_docstr_tok: ["Helper","class","to","build","experiments","or","trials","graph","."]
docstr: Initialize
  
  Parameters
  ----------
  key_to_data:
      Dictionary mapping key (used as node) to related object.
docstr_tok: ["Initialize","Parameters","--","--","--","--","--","key_to_data",":","Dictionary","mapping","key","(","used","as","node",")","to","related","object","."]
code: def __init__(self, key_to_data: dict):
      """Initialize
  
      Parameters
      ----------
      key_to_data:
          Dictionary mapping key (used as node) to related object.
      """
      self.key_to_data: dict = key_to_data
      self.key_to_node: Dict[Any, TreeNode] = {}
      self.root = TreeNode(None)
  
imports: import logging
  import os
  import shutil
  from typing import Any, Dict, List
  from orion.core.io.database import DatabaseError
  from orion.core.io.database.pickleddb import PickledDB
  from orion.core.utils import generate_temporary_file
  from orion.core.utils.tree import TreeNode
  from orion.storage.base import BaseStorageProtocol, setup_storage
label_desc: Use image node_id 1 to create a new _Graph object  with example: obj = _Graph(key_to_data)