code: def __init__(self):
      self.current_stack = []
      self.all_snapshots = SnapshotList()
  
imports: import collections
  import functools
  import timeit
  import traceback
  import weakref
  from json import dumps
  from typing import List
  import numpy
  from .ascii_table import ascii_table
label_desc: Use image node_id 1 to create a new HierarchicalTimer object  with example: obj = HierarchicalTimer()