class_docstr: Sends a message to Slack upon completion/failing of an experiment.
code: def started_event(
      self,
      ex_info,
      command,
      host_info,
      start_time,
      config,
      meta_info,
      _id,
  ):
      self.run = {
          "_id": _id,
          "config": config,
          "start_time": start_time,
          "experiment": ex_info,
          "command": command,
          "host_info": host_info,
      }
  
file_path: sacred/sacred/observers/slack.py
imports: from sacred.observers.base import RunObserver, td_format
  from sacred.config.config_files import load_config_file
  import json
label_desc: Use image node_id 3 for calling the SlackObserver obj's underlying member method code with example usage: obj.started_event(ex_info, command, host_info, start_time, config, meta_info, _id) without return types