class_docstr: The user-facing class that provides metric storage functionalities.
  
  In the future we may add support for storing / logging other types of data if needed.
docstr: Args:
      start_iter (int): the iteration number to start with
docstr_tok: ["Args",":","start_iter","(","int",")",":","the","iteration","number","to","start","with"]
code: def __init__(self, start_iter=0):
      """
      Args:
          start_iter (int): the iteration number to start with
      """
      self._history = defaultdict(HistoryBuffer)
      self._smoothing_hints = {}
      self._latest_scalars = {}
      self._iter = start_iter
      self._current_prefix = ""
      self._vis_data = []
      self._histograms = []
  
imports: import datetime
  import json
  import logging
  import os
  import time
  from collections import defaultdict
  from contextlib import contextmanager
  from functools import cached_property
  from typing import Optional
  import torch
  from fvcore.common.history_buffer import HistoryBuffer
  from detectron2.utils.file_io import PathManager
label_desc: Use image node_id 1 to create a new EventStorage object  with example: obj = EventStorage(start_iter)